Astronomy weather forecast sites
They are customizable to your location – the links below are set to Kendal.
- Astronomical seeing Kendal by metoblue
- Clear Outside
Sky Notes for September – Ian Bradley
The nights are now noticeably drawing with the equinox on September 22nd when there is equal length of day and night. On 31st August/1st September, we have full darkness from just after 22:00 BST until 0400. By the end of the month, 20:45 to 05:15. So, there is plenty of time, much at reasonable hours, to get out and see things. Obviously, see below, the Moon will be in the way at the start of the month. Round about the last full week of the month would be a reasonable time to think about viewing the waxing Moon and a potential Moonwatch.
Aurorae are also being photographed from Scotland, so keep your eyes open.
ISS visible passes
ISS visible passes are all very early morning up until September 12th.
See Heavens Above website for further times.
Mercury is a difficult object in the early evening sky as the plane of the ecliptic is so shallow relative to the horizon at this time of year. Mid-month, sunset is around 19:30 with Mercury a mere 3° above the horizon at that time. This makes it a very difficult object.
Venus is visible all month in the eastern sky at dawn. It rises about 02:00 mid-month.
Mars is now well placed. It rises about 20:30 BST mid-month and transits about 03:00 BST when it is high in the sky with an altitude of 42 degrees.
Jupiter/Saturn are both striking despite being so low on the horizon. They are quite close together in the sky separated by 8°. At magnitude -2.5, Jupiter is considerably brighter than Saturn at magnitude 0.4. Mid-month, Jupiter transits around 20:45 BST, the same time as sunset and so will be hard to see until later when it is lower in the sky.
The two planets make a striking sight in the sky which, as autumn progresses, get closer together as they approach conjunction on December 21st. By the end of November, they will be only 2° apart. Sadly, the really close approach on December 21st will occur in daylight so it will be invisible to us. However, on the evening of December 20th, Jupiter and Saturn will be only 9‘ apart, 1/3rd of a Moon diameter, as they set around 18:00GMT, so well worth looking for.
Uranus is visible throughout the night throughout September, when it rises around 2300 BST, and transits about 0600. At only 4″ angular diameter, and magnitude 5.7, you’ll probably need to use an binoculars or a small telescope to see it. It should appear a slight blue colour.
Neptune is visible all night at around magnitude 7.8 throughout the month. At only 2″ angular diameter, and being so faint, you’ll need to use an optical aid to see it. It should appear a lovely blue colour.
Saturn, 29 September 2020
Imaged from my backyard in Kendal when the planet was only 13° above the horizon. This is looking through the murk and heat haze of the town centre. Skywatcher 10″ 1200mm focal length, x5 Powermate so effective focal length of 6000mm. Canon EOS 750 in movie mode.
Credit: Ian Bradley
Jupiter, 29 September 2020
From my backyard in Kendal when the planet was only 11° above the horizon. Amazed anything to see at all! From left to right, the moons, Io, Ganymede, Europa, and Callisto. Skywatcher 10″ 1200mm focal length, x2 Barlow, so effective focal length of 2400mm. Canon EOS 750 in movie mode.
Credit: Ian Bradley
None of note.
The weather didn’t play fair for the Perseid meteor shower although I did manage to see a couple early one morning in a short-lived break in the clouds. The next showers are:
Draconids meteor shower – October 7 radiates from the Head of Draco and worth looking for a day either side. Because Draco is almost overhead in the evening, this shower tends to be best in the evening rather than morning. But it is an oddball as generally it doesn’t produce that many meteors per hour but is prone to intense outbursts of 100‘s per hour some years. The Moon isn’t an issue early evening as moonrise is around 9pm.
Orionids meteor shower – October 21 At best 10 to 20 per hour and usually better early morning. Tend to be fast-moving meteors which occasionally leave persistent trains and sometimes bright fireballs. Moon sets early evening. Probably best in the few hours before dawn on October 21st and 22nd.
Leonids meteor shower – November 17 One of the better shows with the radiant inside the reverse question mark, The Sickle, of Leo. Typically, 10 to 15 meteors per hour but it does have occasional very strong showings. Best after midnight. The expected peak night is from late night November 16th till dawn November 17th with most meteors in the predawn hours. As there is no Moon to hide the meteors, this could be well worth the effort to see.
The charts are for the mid-September at 23:00 BST. At the start of the month, they are correct at midnight and at the end of the month, 22:00BST. They will also be correct for mid-October at 21:00 BST.
With dark evening skies, there are a lot of things to look out for, be they binocular or telescopic. Prominent but low on the southern horizon are the two gas giant planets, Saturn and Jupiter, which are approaching conjunction in late December. They are about 8 degrees apart during September but by the end of November, they are only 2 degrees apart but set around 19:30.
Looking up, [below] south is at the bottom.
The asterism of the Summer Triangle consisting of Altair, Vega and Deneb is still very prominent, see Moira’s article, and probably the first stars you’ll see as the sky darkens. This is a great time of year to see objects of interest in the constellations at the zenith: Cygnus, Lyra and Cassiopeia.
The Milky Way goes right over your head so there are lots of star clusters to look out for. The most obvious one will be The Double Cluster (NGC 884/869) situated between Cassiopeia and Perseus. In addition, there is Caroline’s Rose, NGC7789, and M103 in Cassiopeia, M34 in Perseus, M29 and M39 in Cygnus for starters. The area is a joy to behold in binoculars on a dark night. There is the globular cluster M62, sometimes known as the Flickering Globular as it seems to change brightness – purely an optical illusion. For wide field imaging photographic targets, what could be better than M31, The Great Andromeda Galaxy and nearby telescopic M33. In addition, there is the North America Nebula complex, NGC7000, in Cygnus and the California Nebula, NGC1499. With a tracked 70mm lens you could capture both NCC7000 and the Pleiades, M45, in one shot, although that combination might be better later in the evening when M45 is higher.
Lyra is an interesting constellation – see Moira’s article. The Ring Nebula, M57, is a splendid fuzzy ring in a small telescope. Just 2° from Vega is The Double-Double, ε−Lyrae, a binary star in binoculars, but with a telescope each of these two stars is seen to be a double star itself.
Whilst on double stars, you must look at Albireo, β-Cygni. This is a beautiful low power telescopic object the brighter star golden and the dimmer one blue.
Four planets on show here. Jupiter and Saturn are low in the west with Jupiter setting round about midnight in the middle of the month. Mars is prominent in the east, rising about 20:30 mid-month. Neptune is visible all night but is only magnitude 7.8 and is quite tiny, 2″ in diameter.
The Square off Pegasus is generally quite obvious. This acts as a good signpost to M31. My preferred solution to find M31 is to star hop from the corner nearest Perseus. This star is Alpheratz, magnitude 2. Following the line of the top of the square towards Perseus there is a fainter, magnitude 3 star, then and slightly higher is Mirach at magnitude 2. Turn a right angle ‘up’ towards the pole and at the second star (both around mag 4) you are almost there. With averted vision M31 should be visible to the eye if the sky is dark, and certainly in binoculars, as a faint smudge. Even in a reasonable telescope, it isn’t much better – always a slight disappointment until you think what it is! Photographically, it I magnificent.
In the deep sky, the crowning object must be the Dumbbell Nebula, M27, planetary nebula. Lovely in a telescope. Nearby there is the Coathanger asterism spanning about 1.5 degrees, a fine wide-field photographic target. The Wild Duck Cluster, M11, so named for the brightest stars, is the most distant open cluster in the Messier catalogue that can be seen with the naked eye. roughly V-shaped arrangement of its Low down, is the Helix Nebula, NGC 7293, another planetary nebula which will be a challenge to view or photograph as it is only as it is only 13.5 degrees above the horizon. There are two bright and large globular clusters M2 and M15 to enjoy, both about magnitude 6 and 12 arc minutes [‘] in diameter.
Have a look for the constellation Delphinus, the Dolphin, which roughly fills the field of view of a x10 pair of binoculars. Nearby between Delphinius and the globular cluster M15 lies the somewhat obscure constellation of Equuleus, the Little Horse or Foal. Even Patrick Moore has very little to say about it!
The winter constellations will soon appear hear. Already the Pleiades, M45, are visible at our map time. Mars is unmissable at magnitude -2.2 and is 21″ in diameter. Uranus is just east of Mars. There are the interesting group of Messier objects, M36, M37 and M38, in Auriga to find which appear as faint misty clouds in binoculars. Most other objects have already been discussed.
Many of the other major objects have already been discussed earlier: M27, M57, M11. In the constellation of Hercules, there are the magnificent (magnitude 6) globular clusters of M13 nearly 17’ in diameter and M92, a mere 11’ in diameter. Also marked is the area where Barnard’s Star resides… see Graham’s article.
Ursa Major and The Plough asterism are quite low mid-month during the map times of 2300 so the region is not at its best. In the handle of the Plough there is the nice double of Mizar and Alcor. This is an easy naked eye double as they are separated by 12 ‘. Mizar, itself, is a splendid telescopic double, with the fainter component separated from the brighter one by 15″. In fact, each component is a spectroscopic binary, so Mizar is at least 4 stars! The pair of galaxies M81 and M82 should be visible in binoculars. There are many other galaxies around the Ursa Major, but they will be better positioned later in the year.