Welcome to the May newsletter. We hope you are keeping well and also have been using the unusual clear weather to good effect and have been enjoying the fantastic skies. I’ve certainly been busy.
It’s looking like some time yet before we can start holding meetings in the Museum. We are not planning meetings in June, July and August at this stage, a slightly longer summer break than normal. I hope that we can be back in the Museum in September but that raises some questions for everyone – not least, for example, is our speaker willing to travel to Kendal!
The committee realises that some members may feel unable or unwilling for personal reasons to attend meetings in person for some time beyond the Government’s hoped for end of restrictions. Therefore, we would be interested to know if people would be willing to go to the museum assuming that the current situation progresses as hoped with an end to lockdown measures mid-June. Please let us know by email using email@example.com. One possibility, which we would need to investigate to see if possible, would be to live-stream the meeting on Zoom. This would require the agreement of the Museum and Kendal College for us to use their network. While not ideal, at least it would allow those members ‘shielding’ to participate.
We’ll look toward producing another newsletter probably early July, depending on what the circumstances are then. We can always alert you to interesting events by email.
Summer is fast approaching. From May 11th, the sky is not fully dark – defined as the sun being at least 18° below the horizon. Astronomical darkness doesn’t occur again until August 3rd. You can still see things in the twilight but with less contrast, so if clear go out and look. Look out for the Perseid meteor shower, visible a day or so either side of August 12th.
As we said previously, we’d welcome contributions to the newsletter from any member. Just get in contact with an email to firstname.lastname@example.org.
So, to conclude, enjoy the summer and keep safe.
Ian Bradley, on behalf of the EAS committee.
Hare Hill Barn, Cartmel Fell – an observing venue?
Not long ago the Society got an email from the owners of Hare Hill, a farm on Cartmel Fell (about 1.5 miles North of High Newton) with amazing dark skies. They have a converted barn which they use for courses and events, and were interested in finding someone who could lead stargazing courses for them. We couldn’t think of anyone immediately (unless you know someone!), but we did enquire about holding observing evenings for the Society at the barn. The answer was Yes! So, Clive Rowland and David Glass went over there to meet the owner and take a look at the facilities. Both concluded that this would be an excellent venue for stargazing, with fantastic views and access to the barn for hot drinks (at cost), power and shelter. We will contact the owners again later this year to set up a session along the same lines as previous ones (covid permitting).
Astronomy News – David Glass
While finishing the last newsletter, we just caught the flight and dramatic end to Starship SN11 in a mid-air explosion. Official word from SpaceX is that the explosion was due to a methane leak around one of the engines. Undeterred, Starship SN15 was moved from the construction area to one of the launch pads on 8/4/21. Here’s how to move a starship (~22 min long, not a lot happens for the first 3 minutes – zoom to 9 minutes for the move). The video also shows new Ground Support Equipment (GSE) tanks for the bulk storage of cryogenic liquids, built on site using the same design principles employed for Starships. These are now in service.
A keen eye can spot differences between SN11 and SN15 – a few obvious ones are heat shielding and a different shape to the inboard leading edges of the flaps (flings, flamps, flaperons or whatever they are actually called, there are lots of names being used!). One commentator points out differences to external vent positions and external pipework, hinting at changes to internal configurations. Perhaps this includes a permanent means of pressurising the methane storage tank instead of padding it with helium (see previous newsletters).
At the time of writing (25/4/21), SN15 has undergone pressure testing at ambient temperature and filling/emptying with cryogenic liquids. There is no indication of when test fires might occur, but they could happen w/c 26/4/21.
SpaceX had a major success on 23/4/21. Dragon Crew-2 was launched smoothly and successfully, and four astronauts boarded the International Space Station on 24/4/21. This launch was significant because both the first stage booster and the Dragon capsule had been used previously, so this was a test of the principle of re-use. Also, the wife of one of the first astronauts to be sent up by SpaceX was on board this flight (and sat in the seat used by her husband). The Falcon-9 first stage booster landed successfully on a drone ship, I think – the live satellite feed kept dropping out.
The whole build up to launch and the launch itself can be watched here (LONG video >4 hours, but zoom to 4h20 to catch the launch): But all that pales into insignificance compared to the main issue that everyone wants to know about. What was the zero-gee indicator?? This time it was Jellycat’s My First Penguin, named GuinGuin by the children of one of the astronauts:
Zoom forward to 4h55m to see GuinGuin put in its first appearance.
Another smooth launch was achieved by Blue Origin’s New Shepard NS-15 on 14/4/21. The capsule got to 348,753 feet altitude, above the Karman line so anyone on board would technically be an astronaut. This time it was only Mannequin Skywalker – however, a dry run was carried out for the boarding of astronauts prior to flight, so perhaps the next flight will have people on board. Both the capsule and booster landed safely. You can watch the astronaut dry run, the launch and landings here.
In an achievement to rival the first powered flight by humans on Earth, a small, light drone helicopter named Ingenuity has flown on Mars. Three times to date (19th April, 22nd April and 25th April). Check out Stuart Atkinson’s excellent Facebook page Postcards from Perseverance to see some amazing images of these historic events.
Making Oxygen on Mars
Perseverance is currently at work on the surface of Mars, and although the pioneering flight of the Ingenuity helicopter has captured the limelight of this mission recently (rightly so!!) there is other amazing science going on as well.
Perseverance is carrying a package named MOXIE (Mars Oxygen In-Situ Resource Utilization Experiment), which is intended to test a means of making breathable oxygen (>98% purity) from the Martian atmosphere which is mostly carbon dioxide. The process is relatively simple, but uses some clever electrochemistry. The feed gas from the atmosphere is first pressurised. it is then passed to a solid oxide electrolysis (SOXE) stack operating at about 800°C, which is effectively solid cathodes and anodes supported on a ceramic structure. The cathode is a catalyst, where a reaction producing oxygen and carbon monoxide from carbon dioxide occurs if an electrical potential is applied across the anode and cathode. The oxygen migrates to the anode where it is collected. The stack has no moving parts, and needs no additional chemicals or solvents apart from the feed carbon dioxide to make oxygen.
MOXIE has so far managed to produce 5 grams of oxygen at a flow rate of about 10 g/hour. The power requirement for this is 300W.
Thinking back to the talk, at our last Zoom meeting, by Dr Hannah Sargent on the importance of using on-planet resources for long-term missions, this result is an important milestone.
Stellar Flares on Red Dwarf Stars
Red dwarf stars have been found with Earth-like planets in close orbits in the “habitable zone”, where liquid water could exist on the surface and life could get a foothold. However, red dwarf stars are known to have exceptionally violent stellar flares which eclipse anything our own Sun has produced to date. A planet in a close orbit in the path of one of these would not necessarily be a friendly place for life. The reasons for these enormous flares on such small stars are the subject of ongoing research.
This month, it was announced that a record-breaking stellar flare was observed on our nearest-neighbour star, Proxima Centauri, and because of patient observing with multiple telescopes it was captured at multiple wavelengths, from far-ultraviolet to millimetre. The star increased in brightness by a factor of 14,000 at ultra-violet wavelengths, and the flare was about 100 times more powerful than similar flares from the Sun. The results will help understand the nature of these flares and improve understanding of how they are produced.
Further information can be found here.
An open-source version of the paper describing the observations can be found here (with a nice introduction).
V1405Cas update – Ian Bradley
Nova V1405 Cas in the constellation of Cassiopeia, is still about magnitude 8. Since first being measured [AAVSO data] on 20th March at around magnitude 7.8, it has faded a little so that currently it is about 8.1. Details on how to find it are in the April Newsletter. It isn’t well placed for me at the moment as it is behind my house until early morning.
SN2021gmj update – Ian Bradley
In the last newsletter I included a photo of a supernova in a faint spiral galaxy NGC3320. I have been following it ever since grabbing an image every few days to see how it behaves…
I have refined my analysis technique, as my initial estimate was as suspected overoptimistically bright. The above image is taken with my 10” Newtonian reflector using a cooled monochromatic camera. An Astronomix luminance L2 filter is used to remove both infra-red and UV light. I took 15 images each of 30 seconds and after calibration and alignment, I averaged then to produce my final image with reduced noise. The images are short exposures to avoid any possibility of oversaturating the supernova or any stars that are of interest for calculating the supernova magnitude. Using the programme AIP4WinV2 – originally distributed as part of Richard Berry’s excellent book “The Handbook of Astronomical Image Processing”, but is now free.
This supernova is believed to be a Type II supernova, identified by the presence of spectral lines of hydrogen, where the stellar core has collapsed following the exhaustion of all elements that can undergo fusion. The infalling material compresses the core, forming a neutron star (or a black hole if the mass if greater than about 40 solar masses), and some of the infalling material bounces back forming a shock wave which blasts off the outer stellar atmosphere, resulting in the ‘explosion’ we see.
In the most common type II supernovae, Type II-P, a plateau appears 30 to 80 days after the peak luminosity. This comes from the shock wave ionising the hydrogen-rich envelope which then slowly recombines over a few months. Whether 2021gmj is of this type, is certainly not yet clear from my data – the reason I intend to keep measuring it as long as possible.
SN2021hiz – Ian Bradley
Stuart Atkinson posted on Facebook on April 15th about a bright supernova SN2021hiz in the faint galaxy IC3322A in Virgo – round about magnitude 13. It was clear that night… so… You can see the supernova clearly outshines the whole galaxy.
The ‘bright’ elliptical galaxy at the left is NGC 4365 and the other edge on spiral at the centre-bottom of the image is IC3322. I’ve counted over 20 other galaxies in this image, presumably all part of the Virgo cluster. My measurement on April 15th gave a magnitude of 12.95 in the visible band using the same technique as for SN2021gmj. I tried to measure again on April 24th but the Moon was too bright and close for useful images.
Thanks to Stuart for the heads up on this supernova.
Moral: I must look more often at the Rochester Astronomy page which lists recently detected supernovae by dedicated research instruments and satellites.