EAS Newsletter for September 2020

A pdf version of this member’s newsletter which includes an additional section on EAS business and developments is issued to all current members.

See also our monthly Sky Notes for objects observable in the sky from Kendal during this month.

Barnard’s Star – Graham Fell

I thought I would write a piece on Barnard’s Star because I have heard of it but have absolutely no idea what it is. So, I’m sitting down at Wikipedia to learn about it and one of the joys of old age is learning something new. Where would we be if we knew it all? I apologise if you (the reader) already know everything about Barnard’s Star because with a newsletter you can just move on down to the next piece – unlike a real live lecture!

Now I know it is the 4th nearest known star after the three parts of the Alpha Centauri system and it is the closest star in the northern celestial hemisphere. It is a Red Dwarf which reminds me that during the lockdown, many episodes of another Red Dwarf were shown on TV so I could relive that great series from long ago. I even liked the new ones they did a couple of years back.

But – enough of this trivia – Barnard’s star is a red dwarf with a mass of only 1/7th that of our sun. Now that surprised me as I thought a red dwarf would be much more massive. Maybe one of our members could do a piece on Red Dwarfs and so explain to me why this star is so small! So, Barnard’s Star is not visible to the naked eye as it has a magnitude of about +9.5 but it is brighter in the infrared than it is in visible light.

Click to enlarge

 

This is a map of where it is and thanks to Wikipedia for the image on the left and Universe Today for the virtual sky image on the right.

 

It was named after an American astronomer in 1916 as he measured its proper motion of 10.3 arcsecs per year relative to the Sun and this is the highest known for any star. Here I’ve taken an animated GIF from Universe Today’s website showing its apparent movement. The movement is from 1985 to 2005 – so a 20- year period.

The apparent motion of Barnard’s Star against the background stars due to its proper motion. The images are roughly 5 years apart.

I am quite amazed to see a star move so much and one that is quite so close to us. It could be that its movement is due to the effect of Dave Lister having curries for breakfast! Dave Lister was only 3 million years old but Barnard’s Star is some 7 to 12 billion years old and so it could be one of the oldest stars in the Milky Way. It has lost some of its rotational energy but its brightness changes indicate a rotational period of 130 days compared to the 25 days of our Sun. With such a long age it was assumed that it would be quiescent in terms of stellar activity but in 1998 astronomers observed an intense stellar flare showing it to be a flare star.

One of the things that always amazes me is that in Astronomy, things are sometimes very different to what we expect. The whole history of astronomy is a universe of surprises every time we learn something new. (Look at what New Horizons found about Pluto!)

This star has roughly 150 times the mass of Jupiter but its radius is only 1.5 to 2 times larger, due to its much higher density. So, Jupiter is a tiny wispy cloud compared to Barnard’s star whereas I always imagine Jupiter as a massive planet thankfully picking up a lot of debris over the last 4 billion years and so saving our planet from death and destruction.

However, Barnard’s star gave us unexpected news in 2018 when an international team of astronomers announced the detection of a super Earth orbiting quite close to the star. Wikipedia tells us that ” was found near the stellar system’s snow line, which is an ideal spot for the icy accretion of proto-planetary the planet material” and this super planet orbits at 0.4AU every 233 days and has a mass of just over three Earths. With an estimated surface temperature of -170°C, it is not likely to be on Dave Lister’s list of planets to visit!

So, after this brief precis of the facts about Barnard’s Star, for which I thank Wikipedia, I can now bore people with all this information.

I am now looking forward to learning so much more – hopefully from members like me who decide to find out some information on one topic and share it with the Society. This short piece alone opens up topics like flare stars, red dwarfs, stars that move, snow lines etc.

New Horizons delivers again – Ian Bradley

You will know of the stunning results from the New Horizons probe from its passage by Pluto and the Kuiper Belt object Arrokoth. Well, it’s just got better… OK, I might be over-egging this!

You are probably aware that the distance to nearby stars can be measured using parallax. That is, the position of a nearby star appears to change relative to distance stars as the Earth orbits around the Sun, with it returning to its original position after a year. This is different to proper motion, in Graham’s article above, that is caused by the actual motion of the star so that the star never returns to than earlier position. Measuring this angular change, the parallax angle, from opposite sides of the Earth’s orbit gives, by simple trigonometry, the distance to the star as we know the Earth-Sun distance, 1 AU ≈150 million kilometres.

The problem is that these angular changes are tiny. The nearest star system to us is the Alpha-Centauri system (α, β and Proxima) is about 4.2 light-years away. For α-Centauri, the angle is only 0.74 arc seconds [symbol “], where 1″ is 1/3600 of a degree. For comparison, Jupiter is currently 45″ and the Moon 1800″ in diameter. The seeing due to the Earth’s atmosphere at the best observing sites on Earth is around 0.1″ and in Kendal is typically 1.5–2”, so you can see this is a formidable challenge requiring sophisticated image analysis. Hence the method only works out to a few hundred light-years for ground-based telescopes. However, being above the atmosphere, the Gaia satellite has measured stars out to 20,000 light-years from near-Earth orbit.

Click to enlarge

Proxima Centauri as simultaneously seen from the Earth and the New Horizons probe. The apparent position change against the more distant background stars is clear. Credit: New Horizons Collaboration

So, what’s new? New Horizons imaged two stars, Proxima Centauri, 4.2 light-years away, and Wolf 359, 7.9 light-years away, at the same time as they were imaged from Earth. The change in position of each star is really clear due to the different viewing perspectives – see the animated gif on the EAS website – and note that the change for Proxima Centauri is larger than that for Wolf 359, as Proxima Centauri is nearer to the Earth.

What’s new here is that New Horizons is 46 AU away from the Earth giving a much longer baseline and hence a larger apparent positional change of the stars against the background of very stars. Whilst this isn’t ground-breaking, and it is unlikely we’ll ever position a Gaia type survey satellite that far out in the near future, I still find this interesting.

Have a look at these two articles here and here.

BepiColumbo mission to Mercury – Graham Fell

Mercury has not been a major target for NASA, possibly because it is so close to the Sun and the fact that it spins so slowly on its axis. Its surface temperature varies from 427°C (which is twice as hot as your oven) to -173°C, which in our house is on the ‘nippy’ side.

As Mercury travels so fast around the Sun (24 to 30 miles per sec) a spacecraft has to be travelling pretty fast to get into an orbit. The Sun’s gravitational pull doesn’t help any deceleration needed to get into an orbit. Then Mercury has no atmosphere so aerobraking is of no use for any lander. So, more fuel is needed to land.

We’ve been there twice – Mariner 10 in 1974 and Messenger in 2012.

Now a third mission is on its way called BepiColumbo and it has two separate spacecraft:

  • The Mercury Planetary Orbiter (MPO) which will get images in several wavelengths to map the surface and exosphere composition. MPO provided by ESA.
  • The Mercury Magnetospheric Orbiter (MMO) will obviously study the magnetosphere and is provided by the Japan Aerospace Exploration Agency (JAXA)

Artist’s depiction of the BepiColombo mission, with the Mercury Planetary Orbiter (left) and Mercury Magnetospheric Orbiter (right) Source: Wikipedia

Hopefully, we will get answers to the following questions:

  1. What can we learn from Mercury about the composition of the solar nebula and the formation of the planetary system?
  2. Why is Mercury’s normalized density markedly higher than that of all other terrestrial planets, as well as the Moon?
  3. Is the core of Mercury liquid or solid?
  4. Is Mercury tectonically active today?
  5. Why does such a small planet possess an intrinsic magnetic field, while Venus, Mars, and the Moon do not have any?
  6. Why do spectroscopic observations not reveal the presence of any iron, while this element is supposedly the major constituent of Mercury?
  7. Do the permanently shadowed craters of the polar regions contain sulphur or water ice?
  8. What are the production mechanisms of the exosphere?
  9. In the absence of any ionosphere, how does the magnetic field interact with the solar wind?
  10. Is Mercury’s magnetised environment characterized by features reminiscent of the aurorae, radiation belts and magnetospheric substorms observed on Earth?
  11. Since the advance of Mercury’s perihelion was explained in terms of space-time curvature, can we take advantage of the proximity of the Sun to test general relativity with improved accuracy?

The mission was successfully launched on 20th October 2018 and is scheduled to enter orbit around Mercury in December 2025 and its primary mission will last for 18 months with a possible extension for one year.

The ESA-JAXA BepiColombo mission to Mercury lifts off from Europe’s Spaceport in Kourou. Credit: ESA

Finally, the Russians are proposing to launch a mission in 2031 to land on Mercury and it is called Mercury P.

The constellation of the month – Moira Greenhalgh

High up in the early September sky, slightly west of south, you will see the well-known Summer Triangle of stars, Deneb in the constellation Cygnus, Vega in Lyra, and Altair in Aquila

Source: EarthSky.org

Let us concentrate on Lyra, only a small constellation but worth learning.

The IAU has around 74 stars in the constellation Lyra, but there are six that are the clearest, a triangle with Vega at one corner, sitting on a parallelogram. Can you have corners in a triangle?

Source: baringtheaegis.blogspot.com

 

The mythology around the constellation refers to the lyre of Orpheus, The inspiration for lots of music. Did you ever sing the Vaughan Williams’ “Orpheus with his lute made the trees, and the mountain tops that freeze, bow themselves when he did sing”? Then there is the Gluck opera Orpheo and Euridice. Who could forget hearing Kathleen Ferrier singing the aria “What is life to me without thee, what is left if thou art dead”? I suspect I may be showing my age here.

Anyway, the story is that Euridice, wife to Orpheus the great musician, was bitten by a snake, died and was taken down into the underworld. Orpheus, distraught, followed her below, charmed Hades with his singing and was allowed to bring her back to the living world provided he led her out and didn’t look back until they were both outside. When he stepped from the underworld he did look, only she was still inside. Hades took her back and it was goodbye to Euridice. He went off on other adventures such as with Jason and the Argonauts where he saved them from the Sirens, but never looked at another woman apparently.

The constellation starting point is the star Vega (α Lyrae), the second brightest in the Northern sky after Arcturus (Sirius being in the Southern hemisphere) and, at this time of the year, it is the first star to pop into view as the sky darkens. Around 12000BCE Vega was the pole star, and will be again around 14000CE, give or take a couple of days. It is a main sequence star like the sun, and was one of the first stars to be photographed, and have its spectrum recorded. It even has a debris disk around it similar to our Kuiper Belt. Sheliak (β Lyrae, bottom right of the parallelogram) is a binary system with the material being transferred between the stars. Beta Lyrae type variables are named after this star. Sulafat (γ Lyrae) is a blue giant and the second brightest star in the constellation.

Source: Torsten Bronger CC BY-SA 3.0

Forming the small triangle with Vega are ζ Lyrae, a wide binary, and ε Lyrae also a wide binary, said to be naked eye separable. Good luck with that! Both components of epsilon are themselves binaries, hence the name “double double”. A small fifth star has also recently been found, so I don’t know what that makes the system “double double single” or “double treble”. Sounds like crochet stitches to me.

The final star of the parallelogram is δ Lyrae, an optical double and part of the sparse faint delta Lyrae cluster. Outwith the parallelogram are κ and θ Lyrae, a red giant and orange giant. Very faint are many other doubles and variables of different colours.

Lyra has many many deep sky objects, of which M57 and M56 are the most well known. M57, the ring nebula, a planetary nebula, looks wonderful in a professional telescope. For an amateur it looks like this below, not coloured but definitely a ring.

 

Credit: Hubble Heritage Team

M56 (right) is a globular cluster and not visible to the naked eye.

Credits: NASA & ESA

The constellation Lyra was within the Kepler mission’s field of view, and many exoplanets have been found, including the 5 planets orbiting Kepler-62 of which at least 2 are within the habitable zone and are likely rocky earth like planets.

Astronomy News – David Glass

Betelgeuse – Still a Puzzle!

Ok, in our last newsletter we reported on a study using the ALMA telescope which indicated giant sunspots as the cause of Betelgeuse’s dimming earlier this year. If only that was the last word – but it isn’t. A new study using the Hubble Space Telescope is pointing towards a different cause, namely the ejection of a giant ball of hot plasma from the surface of the star. Betelgeuse got brighter at ultraviolet wavelengths during this time. This ball of plasma cooled, and dust condensed within it which blocked the light from the star and caused the observed dimming. Observations at ultraviolet wavelengths over time indicated that the plasma was ejected late in 2019 at quite a speed (200,000 mph), and the dimming started about a month afterwards. Here’s a preprint of the paper describing this, which is now published in the Astrophysical Journal.

Artist’s impression (ultraviolet wavelengths) of what might have happened to Betelgeuse late last year. First two images: a blob of hot plasma is emitted from a giant convection cell. Third image: Dust condenses out of the blob as it cools. Fourth image: view of the dusty cloud as seen from Earth.

All images Credit: NASA, ESA, and E. Wheatley (STScI).

And just as things looked like they’ve returned to normal, Betelgeuse appears to be dimming again. Photometry obtained from STEREO-A (Solar Terrestrial Relations Observatory spacecraft), at a time when Betelgeuse can’t be observed from the ground, showed a drop in V-band brightness of about 0.5 between mid-May and mid-July this year. The extent of the dimming is similar to a periodic dimming that happens, but is earlier than expected. You can read the bulletin announcing these findings here.

V-band magnitudes for Betelgeuse over time. The green and blue points are from ground-based telescopes. The red points are from the STEREO spacecraft. The gaps in the ground-based data are times when Betelgeuse is not visible.

Looking at the red points on the right, Betelgeuse is fainter now than it was in mid-April (Dupree et al.)

SpaceX Starships

Following on from the successful “hop” of Starship SN5, Spacex put the next one (imaginatively called SN6) into position at Boca Chica, Texas, fitted a Raptor engine to it and lit it on 23/8/20.

Test firing of Raptor engine on Starship SN6 (credit: SPadre.com via Twitter)

It is possible that SN6 will do a “hop” to about 500 ft as early as the end of August, so keep an eye out for footage! SpaceX is evolving the rocket in small steps. SN7 could be pressure-tested until it bursts and SN8 could have three raptor engines fitted to achieve an altitude of 12 miles. However things proceed, we can expect to see dramatic tests and higher “hops” with more engines in the near future!

(Tiny) Asteroid heading for Earth

Hopefully, you saw the word “tiny” and aren’t digging your underground bunker and stocking it with bottled water and spam to last 7 years. To coincide with the presidential election in the USA on November 2nd, a wee asteroid (2018 VP1) could intercept the Earth. Or not. There aren’t enough observations yet to be certain, and the odds are about 0.4% that it will hit the Earth. This tiddler was first picked up by the Zwicky Transient Facility at the Palomar Observatory (Southern California). It’s an Apollo asteroid, which has an elliptical orbit which crosses Earth’s and an orbital period of about 2 years. It is thought to be about 2m across. The asteroid that put in a spectacular performance seen from Chelyabinsk in 2013 was thought to be about 20m across, so 2018 VP1 isn’t a cause for concern. But it could make a nice trail as it burns up, so let’s keep an eye on forecasts just in case there’s a slim chance that we can catch it!

The observations and the orbital parameters used to estimate the asteroid’s position can be found here  – click on the Orbit Diagram to see how the asteroid could behave.

I was going to include an image of an asteroid hitting the Earth, but I don’t want to start anyone off digging bunkers! Oh, go on then……

2018 VP1 would be too small to see in this artist’s impression. Credit: ALAMY

Giant halo around the Andromeda Galaxy

It’s been known for a good while that late-type galaxies (star-forming, with spiral structure) contain interstellar medium (ISM), i.e. gas and dust between the stars. This is the raw material for the formation of new stars (and planets!), and is also the exhaust from old stars as they evolve and die. However, the ISM doesn’t just stay in the galaxy. It can get ejected (e.g. by supernovae) and fall back in later, extending the timescale over which new stars are formed. A recent study looked at this circum-galactic medium (CGM) around the Andromeda galaxy (M31) using the Hubble Space Telescope. The CGM is so rarefied that it hardly emits anything that can be detected, but it can obscure light from bright objects behind it – in this case, the ultraviolet light from quasars. The study found something amazing – the cloud of CGM around M31 is huge, extending over 1.3 million light-years from the galaxy centre. This is about halfway to our own Milky Way galaxy. If we could see it, it would have a greater diameter than the Plough in Ursa Major. The study also found structure within the CGM that could indicate how it formed and is evolving. You can read the preprint of the paper (now published in the Astrophysical Journal).

If we could see the circumgalactic medium around M31, here’s how it might look. (Credits: NASA, ESA, J. DePasquale and E. Wheatley (STScI), and Z. Levay (background image)

Our own Milky Way probably has a similar CGM halo. We know that M31 and the Milky Way are heading for each other and will collide in billions of years hence – however, if both galaxies have massive CGM haloes then perhaps they are starting to interact already!

EAS Newsletter for August 2020

What’s in the sky this month

For ISS passes, the Moon, the planets, comets, meteor showers and Sky Charts for this summer see our Sky Notes page.

Astronomy News July 2020 – David Glass

Space X

SpaceX have managed two spectacular achievements very recently. The first (2nd August) was the safe return of the two astronauts who went up to the ISS in Crew Dragon at the end of May. This involved a traditional “splashdown” which we haven’t seen in a while! All went well and the astronauts are safely back on Earth. A full replay of the whole event with very informative commentary is available here (You can use the scrollbar to zoom through the quiet bits!)

 

Credit: NASA

The second was the successful “hop” made by Starship SN5 (4th August local time). A single Raptor engine fuelled by liquid methane and liquid oxygen pushed the 60 tonne, 30m tall assembly gradually into the air and brought it down safely again. Some nice clips of the event are here, the second of which shows the leg deployment and the engine in action (although the flames on the side don’t look like they’re supposed to be there)

The assembly included a “mass simulator” on top to represent a payload.

Credit: @austinbarnard45

Watch out for further “hops”, and later on a much higher altitude flight! It looks like field-fabricated rockets can be made to work after all.

SN1987A

Supernovae are rare beasts, but if they happen close enough to us then they can be studied in detail to see how they play out. The results can be compared with models, and teach us a lot about the physics involved. A relatively close one happened in the Large Magellanic Cloud (about 170,000 light-years away) in 1987 and is imaginatively called…wait for it…SN1987A.

For context, the Large Magellanic Cloud with the Tarantula Nebula and SN1987a in 1987. Credit: ESO

It’s long been suspected that a small but massive neutron star should have been left at the centre of the event, but nobody had been able to prove it. However, a recent paper shows that a hot dusty “blob” at the heart of the region is likely to be heated by a neutron star (given the equally catchy name NS1987A). Observations were made with ALMA, a multi-dish interferometric telescope in the Atacama desert, Chile (altitude 16,000 ft), the “How ALMA Works” page is useful. This is a great opportunity to study the early evolution of a supernova, and the results of this study confirm a suspicion that the explosion was asymmetric, with more material blasted out in one direction than the other. No doubt more studies are on their way!

SN1987A remnant, imaged by the Hubble Space Telescope in 2010. The ring is about 6 trillion miles across, and is cause by a shock wave from the event impacting the material in the region. The blobs will merge over time to form a solid ring. (credit: NASA)

There is a lot more on this topic here. In a nutshell, the observations detected a warm ‘blob’ at the expected location of the neutron star. Theoretical modelling indicates that the most likely scenario is that there is a hot (5 million degree) non-spinning neutron star warming the dust.

Extremely high-resolution ALMA images revealed a hot “blob” [red] in the dusty core of Supernova 1987A (inset), which could be the location of the missing neutron star. The green represents the glow of visible light, captured by NASA’s Hubble Space Telescope. The blue colour reveals the hottest gas and is based on data from NASA’s Chandra X-ray Observatory. Credit: ALMA (ESO/NAOJ/NRAO), P. Cigan and R. Indebetouw; NRAO/AUI/NSF, B. Saxton; NASA/ESA

Nova Reticuli 2020

I know that travel to the Southern hemisphere is challenging right now, but people there can witness a nova (Latin: nova stella or “new star”). This was found by a comet-hunting astronomer. More detailed observations indicate that this object is a “classical nova”. These occur when a white dwarf star is in a binary system with a larger star, and the white dwarf accretes matter from its larger companion. Eventually, the mass of material built upon the surface of the white dwarf reaches a critical mass and undergoes a thermonuclear explosion creating the nova, but crucially leaves the white dwarf intact. Classical novae can therefore happen more than once. A more extreme case is a Type Ia supernova, where the mass buildup causes the whole white dwarf to be destroyed.

Artist’s impression of a white dwarf accreting matter from a companion star, triggering a thermonuclear explosion (credit: K. Ulaczyk / Warsaw University Observatory)

Solar Orbiter

Closer to home, the Solar Orbiter mission sent back some remarkable images of the Sun in July. The mission is intended to study the Solar wind and other important topics related to the Sun. These images are taken from the closest distance yet achieved (48 million miles), and were meant to be tests of the instruments. However, the images found numerous hot spots within the Solar corona which are now named “campfires”. These appear to be like Solar flares but are at least a million times smaller. Perhaps this new discovery can help explain at long last how heat energy is transferred to the Solar corona, which is a region above the visible photosphere (at 5,800 K) but is at a temperature of over a million Kelvin. This problem has baffled Solar physicists for a long time! An animation of the observations is here:

The observations are at extreme ultra-violet wavelengths (17 nanometres), associated with very hot material at around 1 million Kelvin.

Who is and isn`t going to Mars? – Richard Rae

Why have there been so many missions to Mars over the last few weeks?

I don’t know about you, but I have noticed throughout the summer there have been numerous missions to Mars announced on the media; a bit like buses, none for ages then several come around the corner all at once!

Let’s have a look at the recent missions and why there has been a spate of Martian orientated activity this July. Also, we will discover some rovers missed the bus completely and we will answer the question; how many years have elapsed since the Curiosity rover landed on Mars?

What does this image tell us?

The route Perseverance will take to Mars. The alignment of the orbits allow travel to Mars in ~6 months (TCMs mark changes to the path of the spacecraft) Credit: NASA

Once every 26 months, the Earth and Mars are positioned in their respective orbits in such a way that it reduces the travel time and minimises fuel spent, allowing spacecraft to travel to Mars in roughly 6 months. In the diagram above you can see Mars is playing catch-up as the spacecraft move outward toward the orbit of the red- planet. The last few weeks have therefore been the optimal time for launching missions to Mars.

Nasa and China are sending roving vehicles to the planet this summer. The United Arab Emirates have also launched a mission to Mars. However, the European Space Agency`s (ESA) mission consisting of its rover named Rosalind Franklin has been cancelled.

In March this year the ESA project was called off due to further testing requirements of both software and hardware. The ESA project ExoMars mission (Exobiology on Mars) jointly with Roscosmos (the Russian space agency) is simply postponed for a further (as you have now guessed) 26 months. The project is now named ExoMars 2022.

Here is Dr Anna Nash AIT & Contamination Control Engineer holding up the ESA Pan-Cam at its working height, after giving a bio-safety lecture at Astrofest this year. (Ok it’s not the actual rover camera but an engineering model)

Curiosity is the current rover that Nasa has on Mars.

Nasa`s rover Curiosity touched down on Mars eight years ago on 5th Aug 2012 and will now soon be Joined by the recently launched rover Perseverance. Credit: NASA

Curiosity landed on the surface of Mars eight years ago; I had to double check this date I cannot believe that it was that long ago. It has travelled 14 miles on the planet, drilling 26 rock samples along its way. The data Curiosity collects is helping to picture how the Martian climate changed over millions of years and why all the streams have dried up. There are globally over 500 scientists involved in this project so I am sure you can see the interest in getting a larger more sophisticated rover onto the planet’s surface.

Curiosity will shortly be joined by the Perseverance rover, so another sky crane landing is destined to take place in February 2021. You can follow the mission (simply named Mars 2020) from here including real-time flight telemetry, and a Helicopter is included…

Ingenuity is the name of the helicopter that will travel with Perseverance to Mars. Primarily this will be a demonstration of technology mission attempting the first autonomous powered flight on Mars. Many further details of this amazing development are available.

UAE first inspiring mission to Mars

The United Arab Emirates successfully launched the Hope probe from Japan. The UAE engineers assisted by American scientists have produced a sophisticated satellite in just 6 years. This will orbit Mars and investigate the planet’s atmosphere. https://www.bbc.co.uk/news/science-environment-53394737

Launch of Hope on July 19, 2020 from Japan’s Tanegashima Space Center on a Mitsubishi H-IIA rocket. Credit: Mitsubishi Heavy Industries

An artist’s impression of the UAE Hope spacecraft in orbit around Mars. Credit UAE Space Agency

Chinese Mission Tianwen-1 a most comprehensive mission

Finally, the Chinese have a mission named Tianwen-1 that will include a lander an orbiter and a rover. This combination of craft including 13 scientific payloads, has never been attempted before. If successful it will herald a major technological breakthrough. The aims here are to extensively survey the entire planet with the orbiter and to send the rover to areas of high scientific interest. See here.

Tianwen-1 Rover Instrumentation including a radar to detect possible pockets of sub surface water.

There is a short article in Nature regarding this ambitious mission. So, you now have an overview of the missions on their way to Mars, I am sure 2021 will be an exciting year in the exploration of the red planet. Keep checking the mission web pages to keep up with developments

Stellar signposts News – Ian Bradley

As the skies are now getting darker in the evening, it is worth refamiliarizing yourself with the layout of the sky to help you find interesting objects. My constellation navigation skills are not that good having, for many years, used GoTo telescopes. If like I do, you generally observe from one place, in my case my backyard, you also develop intuition as what major constellation are about and where they are. But when you go to a new place…

Until the advent of laptops and planetarium software, my default star atlas was Norton’s Star Atlas. It has clear charts of stars down to magnitude 6.5 and many interesting objects – Messier objects, variable stars and double stars for example. It also includes concise information on many astronomical terms and concepts so the atlas is a useful astronomical quick and simple reference document. For star charts, The Cambridge Star Atlas does a similar job although personally I prefer Norton’s.

With smartphones, there are many apps [SkySafari, Stellarium…] to tell you what is where [especially so if your phone has a GPS and compass built in], and provide information on objects but the small screen size is very limiting.

So, what are the alternatives? It’s dark, your mobile is low on power… We come back to the stars themselves. For the beginner, identifying a few of the major constellations can provide great signposts to less familiar ones, and from them to that small faint fuzzy nebula…

The first thing we have to do is orient ourselves correctly. We are lucky in the northern hemisphere to have a star close to the celestial north pole. At magnitude 2, although its brightness varies between 1.86 and 2.14 over a 4-day period, it is relatively obvious and although not particularly bright, there are no bright stars round about it that can lead to confusion.

Stars rotating around the north celestial pole – a 38-minute exposure from Kendal looking along the River Kent. Polaris is the obvious bright star just below the centre of rotation.

The easiest way to find Polaris is to spot the asterism of the Plough (aka The Big Dipper or The Saucepan) in Ursa Major. This is circumpolar and so always visible. It is fairly unmissable and once you’ve tuned in on its shape, you can recognise it even when much of the asterism is covered by cloud. The two stars at the side of the saucepan are known as The Pointers. Once you’ve found The Plough, finding Polaris, and thus north, is easy. Just follow the line of the two pointer stars away from the bottom of the saucepan, and you come to Polaris.

Bear in mind that at different times of the night, the saucepan will be oriented differently. Twelve hours later than the time in the graphic, the saucepan is ‘upside down’ and you have to follow the pointers down to get to Polaris.

 

The Plough is a great signpost to other constellations too with the advantage that it is always visible, that is circumpolar, from our latitude.

It is fairly straightforward from The Plough to find Arcturus in Bootes from the curve of the saucepan handle, the tail of the bear, and if you continue the curve, you will come to Spica in Virgo. Along the line opposite to the pointers gives you Deneb in Cygnus in one direction and Regulus in Leo in the other. One diagonal points to Gemini and the pan top to Capella in Auriga.

Cassiopeia is another obvious constellation which can help you navigate, and again has the advantage of being circumpolar. The obvious W of stars open towards the pole star is familiar to most of us.

Finally, although it won’t really be visible until rather late in the evening in the autumn months, there is the magnificent Orion.

I hope this will help you to quickly find your way around. Once you’ve found the major constellations, you can then, in conjunction with your favourite star chart or app, find the less obvious ones. Good luck.

Right-angle polarscope viewer – Ian Bradley

Following on from David Glass’s suggested project in last month’s newsletter, I can report that I tried it.

I had a Canon Right Angle Finder C in my loft. I bought it many years ago when I was imaging with my Canon 400D on my Meade 8” telescope and frankly, I was unimpressed by its usefulness, hence its sojourn in my loft!

I was thinking of trying David’s project as polar aligning was always a pain, metaphorically and physically. Too many times awkwardly peering through a polarscope. On looking to source a right-angle finder, the penny dropped that I had one in the loft.

I used it to polar align my Skywatcher Adventurer tracking mount – see the picture of Comet Neowise later on in the newsletter. I subsequently needed to add more of the furry side from a velcro strip as it didn’t fit snugly enough. I made another minor modification to the design in David’s article – my finder had four tiny screws attaching the scope to an adaptor plate that fitted my camera eyepiece. The adaptor made a perfect template to drill the four small holes in the film canister, so that’s what I did.

The assembled viewer. The 4 screws, the furry Velcro and the removed adaptor plate can be seen in the photograph on the right.

Would I do anything differently if I did it again?

Yes. I started the large hole in the end of the film canister with a largish drill and then cut it to get the correct clearance. The plastic tends to deform when drilling and the following cutting is so hit and miss. Instead, I’d use a hot soldering iron, or similar, to melt the plastic and create a much tidier and better fit.

Thanks David – hopefully I’ll have less cricked necks now.

Recent Photographs

M5 in Serpens. Imaged from Kendal. Credit: Ian Bradley

Sharp eyes readers will spot that this is a different image from that in the last newsletter – the editor apologises for the wrong photograph!

Comet Neowise from Kendal Castle July 20th, 00:53. Nikon D7000, 35mm ISO1600 4sec at f3.5. Credit: Ted Woodburn

Comet Neowise from Kendal Castle July 20th, 00:43. Nikon D7000, 35mm ISO1600 6sec at f3.5. Credits: Ted Woodburn

Comet Neowise from Kendal Castle July 20th, 00:24. Nikon D7000, 24mm ISO1600 3sec at f3.5.

Comet Neowise from Bradleyfield, Brigsteer Road, Kendal July 16th, 23:47. Nikon D7000, 200mm ISO1600 2.5sec at f4. Credit: Ted Woodburn

Comet Neowise from Orton Scar, July 11th, 23:34. Canon EOS 750D, 35mm ISO800 3 x 6sec at f5. Credit: Ian Bradley

Comet Neowise from Orton Scar, July 11th, 23:27. Canon EOS 750D, 150mm ISO400 64 x 4sec at f5. Individual untracked images aligned on both stars and comet and then stacked and combined.

Comet Neowise from Troutbeck, July 13th, 23:43. Canon EOS 750D, 33mm ISO6400 3.2sec at f4.5. A frustrating night dodging cloud. The people trying to sleep in their camper vans on Kirkstone were probably not too pleased with us being there! Credit: Ian Bradley

 

Comet Neowise from Kentrigg, Kendal, July 19th, 23:43. Canon EOS 750D, 77mm ISO800 4 x 1min at f4. Camera on a Skywatcher Adventurer tracking mount – its first use. Individual images aligned on both stars and comet and then stacked and combined.

Despite light pollution from Burneside, both the bright dust tail and the faint ion tail are visible. Credit: Ian Bradley

EAS Newsletter for July 2020

What’s in the sky this month

For Noctilucent Clouds (NLC), ISS passes, the Moon, the planets, comets, meteor showers and Sky Charts for this summer see our Sky Notes page.

Astronomy News July 2020 – David Glass, Richard Rae & Ian Bradley

Space X and Dragon launch

Dragon crew ship Endeavour docked with the ISS. This photo was taken on June 30th by NASA astronaut Col Doug Hurley whilst on a spacewalk. Credit: Twitter feed Col Doug Hurley@ Astro_Doug
Click the image for a full-page view

SpaceX made history with the launch of NASA astronauts aboard Spacex’s Dragon vehicle for a visit to the ISS.

The last weekend in May marked a turning point in frontier space history. A private company is now providing a “taxi service” to transport astronauts to the International Space Station. SpaceX has successfully delivered 2 astronauts. I hope you were all glued to the live NASA news feeds watching this significant event unfold. Sole dependence on the ageing Russian Soyuz capsules launching from Kazakhstan system is now a thing of the past.

To put this in perspective, the last astronaut to be launched from America was nearly a decade ago in 2011 with the space shuttle. Previously SpaceX has successfully sent un-manned flights to the space station in 2019 using automated docking procedures.

SpaceX transport system for crew and cargo will now be a gamechanger in this rapidly developing industry.

SpaceX (again)

Following on from the spectacular Crew Dragon launch and rendezvous with the ISS, our attention turns back to the Starship project. You’d think that they would have learned something from their high-profile failures – well it seems they might have. Starship SN5 has apparently passed a full cryogenic proof test on 30/6 and is now being fitted with a Raptor engine for further tests.

Earlier, a section of SN7 was tested to destruction. Whether this was intentional wasn’t known at the time. This a classic example of a quasi-instantaneous release of pressurised cryogenic liquid.

Keep an eye out for live coverage of engine testing and any other tests that happen. There are some lively amateur YouTube sites that provide running commentary from their own webcams on nearby apartment blocks trained on the testing site. Here is one with an informative running commentary, local insight and buzzing live chat.

Betelgeuse (Again)

You probably remember the dimming event that affected Betelgeuse last Winter. At the time, everyone thought that the star had coughed out a cloud of dust that caused it to dim at optical wavelengths. It turns out that it was probably giant “starspots” instead. A team used observations at sub-mm wavelengths to investigate what had happened. They found that Betelgeuse dimmed by around 20% at sub-mm wavelengths, which is much more than could be achieved by external dust. The dimming must therefore have been caused by large cooler patches in the star’s photosphere, possibly covering 50 – 70% of the star’s surface.

Here’s a link to the paper describing the results.

The “Missing Link” Between Neutron Stars and Black Holes

It’s been known for a while now that when massive stars end their lives as supernovae, they can leave behind either a neutron star or a black hole. However, no neutron star with mass greater than 2.5 times the mass of the Sun has been found, or no black hole with mass less than 5 Solar masses. There is a gap in mass which nobody understood. However, in August 2019 the LIGO gravitational wave observatory detected an object with a mass of 2.6 Solar masses, as it merged with a more massive black hole. No optical counterpart to the event was detected. here is the paper for this discovery (click on the pdf button).

They conclude “we cannot firmly exclude the possibility that [the less massive object] is a neutron star, nor can we be certain that it is a black hole”.

Pluto and its Sub-Surface Ocean

Montage of enhanced colour images of Pluto (bottom left) and Charon, from the New Horizons spacecraft. (NASA/JHUAPL/SwRI)

Montage of enhanced colour images of Pluto (bottom left) and Charon, from the New Horizons spacecraft. (NASA/JHUAPL/SwRI)
Click the image for a full-page view

The spectacular images of Pluto sent back by the New Horizons spacecraft were just the start. Based on the data received, there is now evidence of a liquid water ocean underneath Pluto’s crust. A team examined the images for signs of stretching or compression, which is what would happen if a sub-surface liquid ocean were to freeze because ice expands when it forms. However, nothing was found even in the oldest terrains, implying that sub-surface water is in a liquid state. This and other key findings are explained if Pluto formed hot within a few tens of thousands of years, and maintained its internal heat through collisions. Sub-surface oceans on planets (dwarf or otherwise) and moons are potential locations for extraterrestrial life, and therefore attract a lot of interest. The paper is behind a paywall , but the abstract is worth a read.

 

Remote Observing with the IRAM 30m Telescope – from Windermere

After poor weather during my last trip to the IRAM 30m telescope in Spain, I was given more time to observe. However, because of Covid-19 travel restrictions, I had to do this remotely from Windermere…

This worked very well, and I managed to get everything observed for my project during the last week of June. I also invited another postgrad student to join in remotely from Preston, to get the experience of observing with this telescope. I’m very grateful to the folk at IRAM, Granada for getting the telescope operational again after the Covid-19 crisis.

Centaurs – Richard Rae

I am sure we were all intrigued to hear about extra-solar system visitors to our solar system such as the interstellar object Oumuamua that was discovered floating through our patch of space in 2017. However, would it not be quite the discovery to find we have had “visitors” from afar joining our solar system many millions of years ago!

Centaurs are small intriguing objects that have orbits that cross those of the outer planets.

New research examining the past orbits of these Centaur objects focuses on their origin and whether or not they could have been present at the formation period of our solar system. The paper by Fathi Namouni (Observatoire de la Côte d’Azur, France) and Maria Helena Morais (Universidade Estadual Paulista, Brazil) suggest that 19 obects have been captured by our solar system that were previously orbiting other stellar systems.

Who would have believed we had so many interstellar objects within our midst?

For the full MNRAS paper click this link.

Neutrinos from the Sun confirm stellar physics theory – Ian Bradley

For many years, the lack of the expected neutrinos from the Sun puzzled astrophysicists. In the 1960’s, Ray Davis’ huge tank of cleaning fluid detected far fewer neutrinos than expected.

The Borexino experiment, Gran Sasso, Italy. A researcher stands in a spherical vessel that 278 tonnes of liquid hydrocarbons Credit: Volker Steger/SPL

The Borexino experiment, Gran Sasso, Italy. A researcher stands in a spherical vessel that 278 tonnes of liquid hydrocarbons Credit: Volker Steger/SPL

Neutrinos are released by fusion reactions inside the core of stars and provide a direct way to measure those processes. They are extremely difficult to detect despite thousands of millions passing through your fingernail each bsecond. The rate of neutrinos detected from the Sun, indicates the rate of fusion inside the core of the Sun. Davis’s experiment only measured 30% of the expected rate. That problem was solved when it was discovered in the early 2000’s that neutrinos can change in their passage from the Sun to detectors on Earth into ones the detectors couldn’t detect. Detectors have improved enormously, both in efficiency and size, since Ray Davis’s day.

nside the core of the Sun, the main fusion process is 4 protons fuse together (in a multistage process) to produce helium and energy [plus two neutrinos]. This proton-proton chain reaction dominates in low mass stars like our Sun. In higher mass stars, a different process dominates – the carbon-nitrogen (CN or CNO) reaction. The nett result is the same, 4 hydrogen nuclei fuse together releasing helium, energy and two neutrinos. In stars like our Sun, the core is too cool for this process to be dominant and only about 1% of the Sun’s energy is produced by this process.

However, the new detectors have allowed this weak process to be detected despite the high background from p-p chain neutrinos. This detection confirms for the first time the decades- old theoretical predictions that some of the Sun’s energy is made by this process and that our understanding of the fundamental fusion processes is correct. More details in this full article [free].

A simple project: a right-angle polarscope viewer – by David Glass

Some of us at least have had the joy of trying to use a polarscope to align a telescope at our latitude. I don’t know anyone with a sufficiently flexible neck or back to do it properly. The solution – make a right-angle viewer. A good recipe is here.

…and I thought I’d give it a go.

I managed to get an old Pentacon (East German) right-angle camera finder on Ebay – it was grubby but it cleaned up very well. I then cut up an old 35mm film canister and made a shaped slot at the back to fit the adapter – and voilà! No more wet/dented knees and sore neck. The viewer is not that heavy and doesn’t affect the polarscope. The film canister provides a snug fit and can be removed without harming the polarscope.

Making a right angle viewfinder for a Skywatcher Star Adventurer camera tracker (Image Credit: David Glass)

Making a right angle viewfinder for a Skywatcher Star Adventurer camera tracker Image Credit: David Glass

Recent Photographs taken by Ian Bradley EAS

The Eagle Nebula, M16 and the Pillars of Creation. A real challenge as always less than 20 degrees maximum altitude from my backyard and directly over central Kendal on 31st May.

The Eagle Nebula, M16 and the Pillars of Creation. A real challenge as always less than 20 degrees maximum altitude from my backyard and directly over central Kendal on 31st May.
Click the image for a full-page view.

This shows just how short the night is at the end of May. The sky brightness was measured using data from the same imaging run used for the picture of M16. The detected brightness in a region with no stars was measured. Pre-dawn is seen by the rapid brightening around 0230. Only date from within the blue region was used to create the M16 image.

This shows just how short the night is at the end of May. The sky brightness was measured using data from the same imaging run used for the picture of M16. The detected brightness in a region with no stars was measured. Pre-dawn is seen by the rapid brightening around 0230. Only date from within the blue region was used to create the M16 image.

The Crescent Nebula in Cygnus powered by a Wolf-Rayet star. Imaged from Kendal.

The Crescent Nebula in Cygnus powered by a Wolf-Rayet star. Imaged from Kendal.
Click the image for a full-page view

M61 in Virgo with supernova SN2020jfo indicated on May13th. This supernova was first detected May 6 2020, so a week earlier. Imaged from Kendal.

M61 in Virgo with supernova SN2020jfo indicated on May13th. This supernova was first detected May 6 2020, so a week earlier. Imaged from Kendal.
Click the image for a full-page view

Globular cluster M13 in Hercules. Imaged from Kendal

Globular cluster M13 in Hercules. Imaged from Kendal.
Click the image for a full-page view

M5 in Serpens. Imaged from Kendal.

M5 in Serpens. Imaged from Kendal.
Click the image for a full-page view

M10 in Ophiuchus. Imaged from Kendal

M10 in Ophiuchus. Imaged from Kendal.
Click the image for a full-page view

M12 in Ophiucus. Imaged from Kendal.

M12 in Ophiucus. Imaged from Kendal.
Click the image for a full-page view

EAS Newsletter for June 2020

What’s in the sky this month

For Noctilucent Clouds (NLC), ISS passes, the Moon, the planets, comets, meteor showers and Sky Charts for this summer see our Sky Notes page.

Astronomy News – Richard Rae

SpaceX makes history with NASA astronaut launch

This last weekend in May marks a turning point in frontier space history. A private company is now providing a “taxi service” to transport astronauts to the International Space Station. SpaceX has successfully delivered 2 astronauts to the International space station. I hope you were all glued to the live NASA news feeds over the weekend watching this significant event unfold. Sole dependence on the ageing Russian Soyuz capsules launching from Kazakhstan system is now a thing of the past

Here is what Stuart Atkinson had to say 

The launch of the first crewed (and it is “crewed”, not “manned”; NASA stopped using that term years ago) SpaceX Dragon capsule to the International Space Station last weekend was both a technological triumph and a fascinating combination of amazing technology and Hollywood hype. Although it will never take the place in my heart left by the sleek Space Shuttle orbiters, with its shiny white hull, its glowing blue, swinging touchscreens and its roomy cabin the Dragon capsule is a thing of beauty, and comparing it to the Soyuz capsules US astronauts have been flying in since Shuttle was retired is like comparing a Formula 1 Ferrari to Del Boy’s ride. Although it might look like a pimped-up version of the old Apollo capsules – and comes back to Earth in the same way, splashing down in the ocean beneath a trio of red and white parachutes – it is much more than that. Make no mistake, the Crew Dragon is a proper spacecraft. The future is here, and it doesn’t have wings.

It was a shame the launch was delayed a few days because of the weather. Not just because it meant all the exciting build-up of the original launch day was wasted – they very generously showed us everything, hours of uninterrupted coverage, from the two astronauts suiting up to the aftermath of the launch cancellation – but because I was at work when the Falcon 9 eventually did leap into the sky, and could only watch snippets of the coverage during my break. But when the Falcon did eventually fly if you listened very, very carefully you could just hear, above the roar of its engines and behind the whoops and cheers and chants of “USA! USA! USA!”, NASA’s bosses letting out a deep sigh of relief. Not just because the risky decision to pay a private company, run by a brilliant but egotistical billionaire, to design, build and launch a crewed spacecraft had paid off, but also because it meant the days of having to cadge lifts up to the ISS from the Russians were finally over. As they mentioned just a few times during the NASA TV coverage America had entered a new age, a new golden age of American astronauts flying an American spacecraft! From American soil! Yeah!

So is this a big deal? Really? Well, yes, it is, although it’s not the spaceflight revolution some are claiming. Crew Dragon isn’t the first reusable spacecraft – hello? Space Shuttle? – but it is a great piece of kit, and will hopefully give the US crewed space program a much-needed kick up the water-cooled backside and allow NASA to let SpaceX (and Boeing, if they get their act together and stop their Starliner capsule’s computers from having HAL-like breakdowns) take care of ferrying people to and from the ISS and start to plan seriously how to send expeditions to the Moon and Mars.

This was a real triumph for SpaceX, no doubt about that. Elon Musk isn’t God, despite what some of his army of worshippers think. He’s not Tony Stark either. But he doesn’t just talk the talk, he walks the walk, and every ambitious goal he sets himself and SpaceX he reaches, eventually, even if his timetables can be unrealistic and his Starship rockets have a habit of blowing up. His thousands of night sky-ruining Starlink satellites might be an abomination, but with Crew Dragon he might just have taken the shackles off NASA’s wrists and given it a chance to explore again.

I hope so.

History

The last astronaut to be launched from America was nearly a decade ago in 2011 with the space shuttle. Previously SpaceX has successfully sent un-manned flights to the space station in 2019 using automated docking procedures.

SpaceX transport system for crew and cargo will now be a gamechanger in this rapidly developing industry.

NASA Space-X Launch transports 2 astronauts to the ISS. Saturday 30th May 2020


NASA Space-X Launch transports 2 astronauts to the ISS. Saturday 30th May 2020

The Dragon spacecraft is capable of carrying 7 passengers into space. Source: (https://www.spacex.com/vehicles/dragon/)


The Dragon spacecraft is capable of carrying 7 passengers into space. Source:
(https://www.spacex.com/vehicles/dragon/)

A unique feature of the Space X Falcon 9 Engine is its ability to land and be used again after delivering its payload into orbit.


A unique feature of the Space X Falcon 9 Engine is its ability to land and be used again after delivering its payload
into orbit.

This video capturing the Saturday landing of the Falcon 9 rocket on a ship in the ocean is well worth reviewing.

The "zero-G indicator" is deployed by a crew member with the Dragon module shortly after second-stage engine shutdown!

The “zero-G indicator” was deployed within the module shortly after second-stage engine shutdown!

Ups and downs of the SpaceX Industry

And just a day before the launch, SpaceX struck disaster at the test facility in Texas. On Friday a SpaceX prototype engine exploded after a couple of minutes of testing. This project is developing propulsion systems for the heavy lift Starship rocket to be used in future piloted and cargo flights to the Moon and beyond.

The Starships prototype engine being tested. The raptor engine is lying horizontally during testing.

The Starships prototype engine being tested. The raptor engine is lying horizontally during testing.

No reported injuries as a fireball engulfs the test site in Boca Chica Texas.

No reported injuries as a fireball engulfs the test site in Boca Chica Texas.

Artemis

ESA – The European Space Agency in signing this contract last week with Airbus to build the third European Service Module (ESM) drives forward the Artemis III project that will be used to transport astronauts to the Moon. A large project involving a collaboration of commercial and international partners.

Exciting developments in the Artmis mission can be followed here.

 

James Webb Telescope Fully Stowed

The James Webb Space Telescopes is said to re-write textbooks after it launches next year (NASA)

The James Webb Space Telescopes is said to re-write textbooks after it launches next year (NASA)

News recently from the James Webb Space Telescopes reports the largest and most complex space science telescope ever built has been successfully folded to the position it must be in when it is inserted into an Ariane 5 rocket. The project has been plagued by delays is set to launch next year.

This most interesting 10-minute video explaining how this huge space telescope will be deployed after its launch next year.

ESPRESSO confirms “Earth-sized” planet orbiting our closest star Proxima b

This is an artists impression of an Earth sized planet orbiting our closest star Proxima b which is around four light years from the sun.

This is an artists impression of an Earth sized planet orbiting our closest star Proxima b which is around four light years from the sun.

The Earth sized planet (1.17 times the mass of the Earth) that orbits our closest star has been CONFIRMED by the unprecedented precision of a Swiss made spectrograph.

The Swiss instrument termed ESPRESSO is installed on the VLT (Very Large Telescope) that operates in Chile. Although the HARPS instrument, an older type spectrograph detected the planet 4 years ago the newer instrument improves upon the previous measurements by a factor of three.

Although the orbit is much closer than the Earth is to the Sun, Proxima b is much cooler. This means being closer to a cooler object the radiation received is comparable to the energy received here on Earth. It is thought liquid water could exist here and the planet would be a candidate for future biomarker research.

And finally, we end on a Supernova …

The first detection was on May 6th 2020 and AT2020jfo is described as a young , rising supernova in the nearby spiral galaxy M61.

Many thanks to Ian Bradley EAS for sending the attached photograph of Supernova 2020jfo.

Many thanks to Ian Bradley EAS for sending the attached photograph of Supernova 2020jfo.

Ian comments – “Supernova 2020jfo In M61, only the second one I’ve ever captured, a supernova indicated by the yellow lines – SN2020jfo – captured May 13 2020. “

Further information on this recent outburst.

EAS Newsletter for May 2020

What’s in the sky this month

For Noctilucent Clouds (NLC), ISS passes, the Moon, the planets, comets, meteor showers and Sky Charts for this summer see our Sky Notes page.

Astronomy News – David Glass

SpaceX

Very recently, SpaceX announced that they are to test a “VisorSat” when they next launch a batch of Starlink satellites. The aim is to reduce their reflection to the point where astronomers can cope with their presence. They should work better than the “DarkSat” they launched as a test a while ago. They won’t remove all streaking on images, though.

Whether this is enough to preserve the night skies and allow quality images for both amateur and professional astronomers remains to be seen.

SpaceX’s prototype Starship

SpaceX’s Starship has just managed to pass a cryogenic proof test without bursting, after another dramatic failure early in April. The next stages are to test-fire the associated Raptor rocket, which may happen very soon, and then try a “Hop”. See film footage of the proof test.

The Mk1 Starship 2nd stage module. It is fully reusable, 9m in diameter and 50m high. This will be launched on the top of a SpaceX’s super- heavy lifter, itself 68m high. The combined rocket will be slightly taller than the Apollo Saturn 5’s 111m.

Here is some footage of an earlier test which was not quite as successful but more dramatic…they have learned a lot since then.

Watch out for press conferences about their launch of Crew Dragon, carrying personnel to the ISS – the first crewed launch from the US for quite a while! SpaceX and NASA are targeting May 27th. NASA Administrator Jim Bridenstine says he is “fairly confident that this launch will be at the end of May, beginning of June.

Fomalhaut b Disappears

Back in 2008, astronomers managed to get the first optical image ever of a A jupiter-sized exoplanet orbiting Fomalhaut, named Fomalhaut b. Unfortunately, new observations using HST show that it wasn’t an exoplanet, and was probably the highly reflective remnants of a collision between two icy bodies. NASA have released a movie to show what happened to the object:

Our own Solar system has lots of icy dwarf planets in its outer reaches, but none have been observed in a collision yet. Catching such a collision in another stellar system is quite an achievement, even if it isn’t a proper exoplanet!

Hubble Space Telescope

he Hubble Space Telescope (HST) reached its 30th year of operation on 24/4/20, and will continue to do amazing work until at least 2025. To celebrate this milestone, NASA, ESA and STSci released a stunning image of a star forming region in the Large Magellanic Cloud (LMC), with NGC2014 on the right and NGC2020 on the left. The region is known as the “Cosmic Reef”. The blue colour is emitted by oxygen atoms and the red by hydrogen and nitrogen atoms, which are very hot or are blasted by ultraviolet radiation from giant newly-formed stars. NGC2020 is associated with a massive Wolf- Rayet star (think back to Joanne Pledger’s talk in February), and is an outer layer of the star that has been ejected.

Go to the website to see the image in all its stunning glory.

C/2019 Y4 (ATLAS)

As mentioned earlier, at the end of April HST was used to capture the disintegrating comet C/2019 Y4 (ATLAS). The outflow of gases from the comet as it approached the Sun might have led to its breakup into about 30 fragments. So, what might have become a comet visible to the naked eye sadly won’t.

Comet /2019 Y4 (ATLAS) as imaged by HST on two days documenting the breakup. In addition, see a good discussion

The Great Debate

It’s 100 years since a major debate took place to decide whether the Milky Way was the entirety of the Universe and all nebulae existed within it, or whether nebulae were other “island universes” outside of the Milky Way. We take the latter as fact today, but only 100 years ago it was still a hot topic with a lot at stake for the champions of both views. For a lively account of what happened and who was involved, go to: https://astronomy.com/news/2020/04/the-great-debate-of-shapley-and-curtis–100-years-later

Access to Astronomy Papers

The astronomy and astrophysics community is fortunate in having access to loads of free academic publications. Many fields of science have their papers behind paywalls, so it’s difficult for people outside of institutions to do research. Two of the most important ones for us are given below.

The Astrophysics Data System (ADS) is a database of published papers going back centuries and is right up to date.

To use it, try clicking on First Author and entering a name in the field that appears (e.g. Hubble). Then click on date and enter 1926-1930 in the field that appears. Then click on the magnifying glass, and you’ll get a list of papers that fit the criteria. Click on a paper, and you’ll get the details (with an abstract if one exists), and on the right you can access the actual paper (subject to certain paywalls!) using the small icons e.g. Publisher, pdf symbol. Try the 1929 paper (no. 6 in the list) – you’ll see the first evidence that the Universe is expanding! You could also try seeing just how far the database goes back – try searching on Herschel 1770 – 1790 and see if you can find a paper entitled “Account of a Comet”. What had he actually discovered? You can also search on specific keywords e.g. pulsar, supernova, M31.

Another highly valuable resource is ArXiv This is where people put their papers that are on the verge of publication, free of paywalls. While it is cutting-edge and free, the papers aren’t necessarily peer-reviewed and a few may not stand up to scrutiny. Some April 1st postings are brilliant (e.g. explaining the severe and long Winters in Westeros!). You can search on specific authors or topics of interest to see the latest papers on a topic. You will see an Astrophysics category link lower down the page, to make the search more specific.

A simple project – star trails

This is possibly the simplest astrophotography thing you can try bar a single shot. I haven’t done this for many years until a few days ago, so it was all guesswork. I was very pleased with the result.

  • A reasonable digital camera, DSLR or mirrorless
  • A fairly wide-angle lens. The typical kit lens that most DSLR cameras come with would suffice – these are usually 18-55mm or similar at its widest [smallest number]
  • A tripod
  • A remote release of some form – maybe the camera software or it might even be possible with a modern camera to use a mobile app. [I haven’t tried this .] I just use a simple switch that plugs into the 2.5mm socket in the side of my Canon DSLR
  • A fully charged battery and a memory card with sufficient space
  • A reasonably dark site – better without a strong Moon
  • An interesting foreground makes a better picture e.g. a church tower, an interesting building, a tree…

Turn off the autofocus and image stabilisation. Set the camera to manual and open up the lens to its biggest aperture – smallest f-number. Set exposure to 30 seconds and a reasonable iso – not too low or too few stars will be visible, equally not too high or it becomes cluttered. Some experimenting is required to get these right. There is no right – just does it look good! If 30 seconds exposure isn’t enough for your lens, try longer although without an intervaometer, that could be rather tedious.

The hardest bit is getting a reasonable focus. Autofocus will not work. Looking at a realtime image, Liveview, on the back screen helps a lot. Initially manully focus on a distant object and then find a bright star. Zoom right in [on the Liveview screen and not the lens zoom!] on the star [or even the Moon or Venus] and manually adjust the focus until the star is as small as possible. If your camera doesn’t have the Liveview facility, just take a shot, look at it zoomed in, and repeat. That is just a bit slower and more fiddly.

Take lots of sequential photographs for about an hour or so. To get the trails image, simply use the free startrails software available from , add the jpeg images [RAW files are not required which saves space on the memory card] and ‘press’ the button. It even sorts out the foreground for you an can give you a timelapse video if you want one.

The picture above was taken on my Canon EOS 750D with a Tokina 11-16mm wide angle lens, set to 11mm and f2.8. 76 exposures of 30 seconds each at ISO800. I set the camera to repeatedly take pictures, this symbol on my Canon and triggered the shutter. It continues to take images until I released the trigger – hence the switch. I was laid on the side of the River Kent, 50m or so from my house, with a bottle of beer in one hand, being buzzed by hunting bats whilst I stared at the sky… many satellites and one solitary late Lyriad meteor. A few minutes later at home, I had that picture.

Go on, have a go.

Recent Photographs

M97 the Owl Nebula and M108. Imaged from Kendal

M97 the Owl Nebula and M108. Imaged from Kendal

M51, the Whirlpool Galaxy. Imaged from Kendal

M51, the Whirlpool Galaxy. Imaged from Kendal

M94 in Canes Venatici. Imaged from Kendal

M94 in Canes Venatici. Imaged from Kendal

 
M63 The Sunflower Galaxy. Imaged from Kendal.

M63 The Sunflower Galaxy. Imaged from Kendal.

 M104 The Sombrero Galaxy A bit of a challenge as only 20° above the horizon and directly over central Kendal. M63 The Sunflower Galaxy. Imaged from Kendal

M104 The Sombrero Galaxy
A bit of a challenge as only 20° above the horizon and directly over central Kendal.

NGC4565, the Needle Galaxy in Coma Berenices. Imaged from Kendal.

NGC4565, the Needle Galaxy in Coma Berenices. Imaged from Kendal.

EAS Newsletter for April 2020

What’s in the sky this month

For the moon, planets, Comet C/2019 Y4 (Atlas) and deep-sky objects, see Ian Bradley’s notes, links and illustrations on our Sky Notes page.

Astronomy News – David Glass

A quick round-up of just a few fascinating things that have been publicised during March and early April!

Betelgeuse

Our neighbourhood red supergiant star Betelgeuse has caused quite a stir recently, thanks to a relatively rapid dimming event monitored by (amongst others) the Association of Amateur Variable Star Observers (AAVSO). Is it building up to go supernova? Probably not. At our March meeting, we saw evidence that it is brightening up again. Pop outside when the sun has gone down, and (cloud permitting) you can see for yourself that Orion is looking as it should again.


Thiscomparison image shows the star Betelgeuse before and after its unprecedented dimming. The observations, taken
withthe SPHERE instrument on ESO’s Very Large Telescope in January and December 2019, show how much the star has faded
andhow its apparent shape has changed.

So, what happened? In March we thought that a large puff of dust in our direction had caused the dimming, but the evidence was still a bit sketchy. The apparent shape change is indicative of that. However, new research published in March showed that the “surface temperature” of Betelgeuse was only slightly cooler as a result of the dimming. The surface of a star is not something we could stand on but is where electromagnetic radiation from the body of a star can escape unhindered (and do useful things like warm planets and get measured by astronomers). So, the dimming wasn’t due to Betelgeuse cooling off, and it was business as usual except for something in the way of our line of sight.

An exercise:

  1. Go to the AAVSO website
  2. hover the mouse over data
  3. data access and click on Light Curve Generator v2
  4. type in Betelgeuse as the star name. use the “Select Bands” radio button and tick the box below the green square for V band (you can pick others as well if you wish, like the black circle for plentiful visual estimates)
  5. click on “Julian Day”, and select “Calendar Date” from the drop-down menu
  6. You can adjust the dates plotted. When you’re done, click “Send” – and admire the result!

SpaceX Starship SN3

Hot on the heels of SpaceX Starship SN1 launch and second stage separation (unintentional!), Starship SN3 was put in position for testing. For some great footage of this happening

A live webcam is also available.

Live Webcams

There are some fascinating astronomy-webcams to explore if you’re stuck at home. Here are three to be going on with:

Satellite and Telescope Models to make at home

If you’ve got access to a printer, it’s easy to get the designs to make some impressive 3D models of your favourite satellites or spacecraft and some ground-based telescopes. Here are some of the designs out there:

There are quite a few others out there – if you go to the home page of a satellite (in Earth orbit) or spacecraft (away from Earth Orbit) and look in the outreach sections, you should find something to build. Send us the photos of what you built!

Astronomy Podcasts – Clive Rowland

You may be interested in listening to podcasts on astronomy – here are a couple

Recent Photographs – Ian Bradley


Venus on 20th March. From a video taken with a Meade LX200R a, x2 Barlow and a Philips SPC900NC webcam


M51, the Whirlpool Galaxy. Imaged from Kendal

101 The Pinwheel Galaxy. Imaged from Kendal


M101 The Pinwheel Galaxy. Imaged from Kendal

M97 the Owl Nebula. Imaged from Kendal


M97 the Owl Nebula. Imaged from Kendal

M81 & M82 in Ursa Major. Imaged from Kendal


M81 & M82 in Ursa Major. Imaged from Kendal

 

Notes and links from the March 2020 meeting

Welcome and Notices Ian Bradley EAS

The society has been notified of two reflector telescopes for sale, one a 5″ Sky-Watcher with an equatorial drive for £60 the other a Meade on substantial Equatorial tripod for £300. Use the main menu EAS About Us/Contact page for details.

Astronomy News David Glass EAS

Betelgeuse

News this month started off with the latest on Betelgeuse, which is now starting to brighten according to photometry from the Association of Amateur Variable Star Observers (AAVSO). A substantial emission of dust could be responsible, based on the latest images from ESO’s Very Large Telescope (VLT). One very high-resolution image shows that Betelgeuse has changed in shape and has a darker patch compared to a year ago. Another shows a substantial dust cloud around the star emitting in infra-red. We’ll keep an eye on the situation in case anything else happens!

Betelgeuse light Curve to beginning of March

Betelgeuse light Curve to the beginning of March

Launching Satellite Clusters

Next, SpaceX and their Starlink satellite clusters. The Russian Academy of Sciences is taking the issue of their impact on astronomy to the United Nations. A report from the European Southern Observatory (ESO), examining the impact of many small satellites on ground-based optical astronomy, found a limited impact on deep imaging of very small areas of sky (apart from cost) and on the visual appearance of the night sky. However, the impact on wide-field surveys is likely to be significant. They have not yet addressed radio astronomy, which will be covered in another report.

SpaceX Starship SN01 Test

The testing of the cryogenic liquid tanks for the SpaceX Starship SN01. During a cryogenic proof test using liquid nitrogen (a safer option than fuel or oxidant!), the lower liquid oxygen tank split causing the whole assembly to lift. On crash-landing, the upper liquid methane tank was propelled away. We await definitive information on the causes of this failure, but the fault could be related to welds joining the stainless steel bands and plates that form the tanks. When in service, the Starship (plus first stage) should be capable of sending payloads of over 100 tonnes (equivalent to over 3 fully-laden 40-foot containers) into low-Earth orbit. It is also intended for travel to the Moon and beyond

Earth has a New Moon

The Earth has a new moon (for now!). 2020 CD3 is about the size of a small car (not a Tesla!) and has a 47-day elliptical orbit. It is likely to leave orbit soon.

Listening to meteors

David brought to our attention a streaming service submitted by our amateur radio member, Clive Rowland: the Meteor Echoes project is now live and streaming on: meteors entering the atmosphere.

What’s in the Sky for March 2020 Ian Bradley EAS

For Constellations, Binocular objects, Deep Sky objects ISS passes visible this March see our What’s in the Sky this month by Ian.

Hide and Seek with Wolf Rayet Stars Dr Joanne Pledger Guest Speaker

Dr Pledger quickly introduced us to Wolf Rayet Stars (WR stars): massive, highly evolved and bright stars. Over 8 solar masses, over 1,000 times brighter than our sun, and extremely hot at 30,000K, compared to the sun at 6,000K, their effect on their physical environments can be extreme and lead to a number of theoretical anomalies and outstanding questions.

Image of WR 124 and the nebula M1-67 in Sagittarius. Captured by the NASA/ESA Hubble Space Telescope.

WR 124 and the nebula M1-67 in Sagittarius. Captured by the NASA/ESA Hubble Space Telescope.

First categorized in the mid-19C by the unusual broad emission-lines in their spectra that lack the element hydrogen (the fuel of most stars during their evolution). While many types of stars have mass enough to progress to the second element, helium, after burning all their hydrogen, WR stars feature not only helium but nitrogen, carbon, silicon, and even oxygen in their spectra.

Wolf–Rayet stars turn out to be a normal stage in the evolution of very massive stars. Initial categorization was into two types, WN and WC, depending on whether the spectrum was dominated by lines of nitrogen or carbon-oxygen respectively. Some show traces of hydrogen in their spectrum suspected of being either older Wolf–Rayet stars (WNL stars) with dust envelopes (WN stars) or, on the other hand, young massive stars evolving through a short life cycle.

WR stars, with their high mass, are mooted as possible progenitors of supernovae, particularly the newly-discovered types Ib (lacking hydrogen) and 1c (lacking hydrogen and helium) supernovae. Nonetheless, no conclusive identification has yet been made of such a progenitor.

Before the final supernova explosion, high mass stars can survive the Red Supergiant stage, expelling their outer layers in a nova event, to retract and progress on to become WR stars – burning through the elements heavier than hydrogen and helium. The ejected high-temperature elements and interstellar dust may be energized by high radiation and stellar winds from the WR star to become a Wolf–Rayet nebula.

WR 31a with a Wolf–Rayet nebula Credit:by the NASA/ESA Hubble Space Telescope.

WR 31a with a Wolf–Rayet nebula Credit: NASA/ESA Hubble Space Telescope.

Notes and links from the February 2020 meeting

Welcome and Notices David Glass EAS

Neighbouring events

David Glass welcomed everyone to the meeting and described the Moonwatch that took place on 1st Feb, Brewery Arts Centre. David, Graham Fell and Ian Bradley attended. In spite of poor forecasts, the half-moon put in an appearance for about an hour and several people looked through David’s 20cm SCT (28mm eyepiece with Lunar filter) at the terminator – and were all seriously impressed. Next one is the 29th of this month.

David also publicised the Dark Skies Festival run by the Friends of the Lake District and encouraged people to get involved. FoLD is leading a campaign to get the Lake District accredited as a Dark Skies Reserve, which deserves our support. David also gave a quick summary of his observing visit to the IRAM 30m telescope, Spain – a warm welcome there as ever.

Sky Notes for February 2020 Phil Morris EAS

For the Moon phenomena, February planets, the winter constellation, Orion, and more see our Sky notes for this month. for this month by Phil:

Astronomy News for January 2020 part 1 David Glass EAS

Betelgeuse

One item which hit the headlines recently is Betelgeuse – it has dimmed significantly over the last few weeks, and there is speculation that it is about to go supernova. On 6th January this year, AAVSO put out a bulletin urging their observers to get photometric and spectroscopic observations urgently. Looking at the light curve from AAVSO over the last 10 years, Betelgeuse has definitely dimmed and is less than 30% as bright as it was early in 2019. Whether this indicates that it is about to blow is not certain though. Another explanation is that it has puffed out stellar winds in our direction that are laden with dust (this type of star is known to do that). Watch this space!

Betelgeuse and Minimum graph

Betelgeuse and Minimum graph

Launching Satellite Clusters

Another significant item is the recent launch of a cluster of 60 250kg satellites, as part of an eventual network of thousands to provide broadband across the planet. Early examples are already affecting astrophotography and are visible to the naked eye. The longer-term effect on ground-based astronomy and astrophotography is not looking good at the moment. On 8th of this month, the American Astronomical Society (AAS) held a meeting to discuss the scheme and its implications, and it is understood that the Royal Astronomical Society (RAS) has put together a working group with a similar aim. Whether this is in time to mitigate the worst impacts remains to be seen.

The Transiting Exoplanet Survey Satellite (TESS)

On a brighter note, the TESS satellite has discovered a rocky planet (TOI 700d) around an M-class dwarf star about 100 ly distant, which orbits within the star’s habitable zone. This star was mistaken for a The sun-like star initially, but a team including a high-school student, have put this right. The star appears to suffer fewer violent flares than other similar stars, so the prospects for conditions favourable to life on this planet are greater.

Alston observatory workshop and lectures

Closer to home, UCLAN is running free astrophotography workshops at their Alston observatory. The official closing date for applications is 16th January. See details.

Also, UCLAN is holding their next public astronomy lecture on Friday 24th January. Details to follow.

Astronomy News for January 2020 part 2 Richard Rae EAS

Richard Rae gave a report from Astrofest 2020 that was held in London. There were many new exciting missions to report, including the comet intercept and Asteroid deflection projects. Jan Worner the head of the European Space Agency came to give a talk on ESA and all the missions and partnerships in which it is involved. He ended by commenting ESA will not go back to the Moon but it must be seen as going forward to the Moon.

Astrofest poster

Things to Come Stuart Atkinson EAS

Stuart gave a very informative talk entitled “Things to come”

The talk focused on the companies and partnerships that would take humans into space and highlighted the possibility of space tourism in the not too distant future.

Virgin Galactic may be one option for tourists to gain access to space albeit for about three minutes!

EAS meeting and Virgin Galactic impression

Blue Origin is a rival to Virgin Galactic and may offer longer and cheaper trips into sub-orbital space

Boeing`s Starliner project is a serious attempt at providing a route for a crew to travel to the ISS. Although this project has had some recent setbacks.

The main contender to Boeing`s Starliner is Elon Musk`s Crew Dragon. This is ahead of development and has recently successfully tested its escape pod mechanism.

Crew Dragon’s first crewed test flight to the ISS is due in March 2020.

Crew Dragon’s badge

The SpaceX Starship proposed project is huge! It will be able to put 100 people into space and travel to the Moon and Mars.

SpaceX Starship project

Other projects briefly covered were:-

Artemis 2028 impression

Stuart ended by saying that Elon Musk considers by the end his life he will be living on Mars.

Notes and links from the January 2020 meeting

Welcome and Notices Ian Bradley EAS

Neighbouring event

As part of Cumbria Dark Skies Festival 2020, Cockermouth Astronomical Society will be holding two events on Saturday 22nd February 2020:

  1. from 1- 4pm in Keswick’s iconic Moot Hall “An afternoon of talks by some of the UK’s top astrophotographers” Speakers:
    • Jeremy Hunt – Astrophotographer and author of “Astrophotography and the lifecycle of stars”
    • Stephen Cheatley – Blackpool based professional photographer with beautiful images of the night sky and famous UK landmarks
    • Pete Williamson – FRAS, broadcaster, astronomer and consultant on the Faulkes Telescope Educational Project
    Booking: contact Jeremy Hunt (07535540499) or via the Cockermouth Astronomy Society Facebook page Capacity 45 – so there may not be seats available on the day £5 per talk; or £10 for the entire session.
  2. from 6:30pm a Public stargazing session that evening 18:30 – 21:30 in Crow’s Park, Keswick – free See our Neighbouring Events page

Observing Session

Weather permitting we hope to hold an Observing Session Thursday 16th January.

Sky Notes for January 2020 Ian Bradley EAS

This January will be a good time to follow the comet Comet/2017 T2 (Panstarrs) with binoculars moving through the Milky Way between the constellations of Perseus and Cassiopia

On January 27th at sunset, Venus and Neptune very close together. Venus – the unmissable bright ‘star’ in the South West at 6pm. Neptune is magnitude 7.9 – so you will need binoculars at least.

Moon compared to Venus and Neptune




The Moon compared to Venus and Neptune

For Orion and more on our EAS Sky notes for this month.

Astronomy News for January 2020 David Glass EAS

Betelgeuse

One item which hit the headlines recently is Betelgeuse – it has dimmed significantly over the last few weeks, and there is speculation that it is about to go supernova. On 6th January this year, AAVSO put out a bulletin urging their observers to get photometric and spectroscopic observations urgently. Looking at the light curve from AAVSO over the last 10 years, Betelgeuse has definitely dimmed and is less than 30% as bright as it was early in 2019. Whether this indicates that it is about to blow is not certain though. Another explanation is that it has puffed out stellar winds in our direction that are laden with dust (this type of star is known to do that). Watch this space!

Betelgeuse and Minimum graph




Betelgeuse and Minimum graph

Launching Satellite Clusters

Another significant item is the recent launch of a cluster of 60 250kg satellites, as part of an eventual network of thousands to provide broadband across the planet. Early examples are already affecting astrophotography and are visible to the naked eye. The longer-term effect on ground-based astronomy and astrophotography is not looking good at the moment. On 8th of this month, the American Astronomical Society (AAS) held a meeting to discuss the scheme and its implications, and it is understood that the Royal Astronomical Society (RAS) has put together a working group with a similar aim. Whether this is in time to mitigate the worst impacts remains to be seen.

The Transiting Exoplanet Survey Satellite (TESS)

On a brighter note, the TESS satellite has discovered a rocky planet (TOI 700d) around an M-class dwarf star about 100 ly distant, which orbits within the star’s habitable zone. This star was mistaken for a The sun-like star initially, but a team including a high-school student put this right. The star appears to suffer fewer violent flares than other similar stars, so the prospects for conditions favourable to life on this planet are greater.

Alston observatory workshop and lectures

Closer to home, UCLAN is running free astrophotography workshops at their Alston observatory. The official closing date for applications is 16th January. See details.

Also, UCLAN is holding their next public astronomy lecture on Friday 24th January. Details to follow.

Meteorite Zoo by guest speaker Mike Armstrong LaMAS

Mike Armstrong began with a brief history of meteorites. They have been recognised in the history of most cultures. Except for Europe, surprisingly, a meteorite was appreciated as being from beyond the sky. American Indians venerated a Meteorite from the sky despite its having fallen pre-ice-age. The issue in Europe would seem to be that nothing could stray from perfect heaven down to corrupt earth before the Copernican Revolution.

A modern definition is a piece of rock from outer space (a meteoroid) that survives an entry through the atmosphere (a meteor) to land on the surface of the Earth when it becomes a Meteorite. If less than 2mm a meteorite is classified as a micrometeorite. An average two will be found in the dust and debris on a roof.

Chondrite Meteorite

Chondrite Meteorite

Mike illustrated the breakdown of meteorite categories. Most meteorites are stony chondrites originating in the formation of the solar system. A full classification is complex.

All can be identified by the evidently melted surface from vaporisation during entry. The shape most often can fit into three categories resulting from the dynamics of the entry; spin will be conical (similar to a nose-cone heat shield), an unperturbed fall leaves less melting on the top whereas a tumbling rock will show erratic melting marks like a thumbprint.

Mike went on to illustrate famous meteorites and meteor craters. Surprisingly, the Barringer Meteorite Crater in Arizona and the Tunguska event in Russia was most probably airborne vaporising, explosions leaving no solid remains.

Barringer Crater, Arizona


Barringer Crater, Arizona

Russian Meteor explosion Site




Russian Meteor explosion Site

The best chance of finding a meteor is after a witnessing a fireball and a sonic bang (up to 20 miles distant). An elliptical, Strewn Field fall area may be evident where the smaller meteorites are to one end indicating the direction of fall.

Otherwise, meteorites may be purchased from £30.

Only two direct hits on humans have been recorded though property has been damaged.

Notes and links from the December 2019 meeting

Welcome and Notices Ian Bradley EAS

Ian welcomed members, new members and made a presentation:

Presentation to Anna Hall

Ian made a presentation to our host Museum Curator of long service. Anna has opened up the premises, making tea, sitting through meetings to lock up after we leave for more than a decade until recently.

Anna Hall

Announcements

  • A Skywatcher HEQ5 Pro mount and tripod are for sale – please express your interest through our EAS Contact Page.

Sky Notes for December 2019 – Moira Greenhalgh EAS

After sunset at around 7 pm the Moon, Saturn and Jupiter float in a line above the southern horizon. Moira guided us to the location of the 5.7 magnitude planet Uranus that is worth the effort even with low-powered equipment for its pure colour:


Uranus – NASA/JPL-Caltech

Moira drew our attention to The Square of Pegasus which still rides high in the sky in the evening before Orion becomes prominent in midwinter. In particular, the local galaxy Andromeda, the only galaxy visible to the average person’s unaided eye (See quiz, below).

See also our EAS Sky notes for December.

Quiz – set by David Glass and Richard Rae EAS

David organised use into teams of three and challenged the meeting to two sets of 20 questions. Contrary to the fear that David would challenge us with solutions to his latest research, there was a distinct orientation in favour of practical astronomy, previous EAS talks and what ought to be common knowledge.

So, what is the farthest object visible to the unaided eye? Before going through a list the thousands of visible stars (which are all in our own galaxy)- see Sky Notes above.

Social Evening

While David calculated the overall winners the second half of the meeting broke up into a social evening with fare kindly laid on by hardworking members and the museum curator.