The Night Sky in May, 2020

May, June and July are not good months for observing since the days are long and the nights are short and not very dark. However, the nights are warm and sometimes too hot and muggy to lie in bed if you can't sleep. This is a good time to go into the garden, open a reclining chair and browse the night sky with a pair of binoculars. The Milky Way can look magnificent at this time of year. You may also wake before dawn in which case you can look out to see the morning objects in the sky.

On May 1st, the Sun will rise at 05:35 and set at 20:41 BST. By the end of the month it will be rising at 04:49 and setting at 21:28 BST! There will be a New Moon on May 22nd and a Full Moon on May 7th. The best time for stargazing will therefore be the middle of the month.This is not a bad month for planets! There are some to be seen. For many weeks now we have become used to the magnificent sight of Venus blazing in the west after sunset. However this is about to change. The planet will be at inferior conjunction on June 3rd. This means that it will be lined up directly between the Earth and the Sun. Thus the light from the Sun will drown out Venus and it will no longer be visible to us. However you may find it interesting to watch Venus change from the beginning to the end of the month. Venus is a rocky, volcanic planet but it is covered in a very thick atmosphere consisting of carbon dioxide laced with sulphuric acid. However this atmosphere is very reflective and reflects the Sun's light towards us. This is why Venus is so bright. It is not possible to see the rocky planet with binoculars or a small telescope but you can see Venus's phases through a small telescope or powerful binoculars. The phase depends on the angle between the Sun, Venus and the Earth. You can see a crescent Venus, a full Venus, a new Venus and anything in between just as you can with the Moon. At the beginning of the month Venus will be shining very brightly at magnitude -4.4 and will display a beautiful crescent with the disc 24% illuminated. Remember that the lower the magnitude is, the brighter the object. A magnitude of -4.4 is very bright! Venus will set about 4 hours after sunset. By the end of the month it will shine at magnitude -3.7 and will be a slender crescent with less than 1% of the disc illuminated. It will also set only 30 minutes after sunset. Mercury reaches superior conjunction on May 4th which means it is on the opposite side of the Sun from the Earth and directly in line with them. So we can't see it at all. However after this it will re-emerge dramatically into the night sky soon after sunset. It will be very bright and quite close to Venus on May 21st and 22nd so it should be easy to spot. Mars is still quite low in the morning sky and not very bright. However it will brighten gradually throughout the month. The best time to see it is around 3 am on May 31st. Both Jupiter and Saturn are still morning objects. They are quite close together and the best time to see them both is from 2am to 5am on May 31st. They will rise in the south-east and then gradually move into the south. Saturn is in the of Capricorn and Jupiter is in Sagittarius. The star charts below clearly show this. The first is the sky in the south-east at 02:00on May 31st. The second is the sky in the south at 05:00 on the same day. There is something to look forward to in December. Throughout this year, Jupiter and Saturn will gradually move closer together. By December 21st they will be so close to each other that they will look like one object to the naked eye. You can separate the two in binoculars but if you have a telescope then look at them before they get too low in the sky. You may have the great pleasure of seeing Saturn and its rings and Jupiter with its belts and moons all in the same field of view. I will remind you about this later in the year. There is an exciting event this month. Comet ATLAS (C/2019 Y4) was discovered by the “Asteroid Terrestrial Impact Last Alert System” in Hawaii on December 28th 2019. They have been monitoring it very closely ever since. I haven't mentioned it before since it wasn't expected to be visible to the naked eye. However it is now in the inner solar system and heading towards the Sun. It has brightened more than expected and may well be visible to us in the naked eye or in binoculars. You will need to look in the north-west near midnight for the skies to be dark enough. The star chart below shows the sky at that time on May 17th. Many of you will now be familiar with that part of the sky. You can clearly see the W shape of Cassiopeia to the right. To the left of it is Camelopardalis the Camel. Below that is Perseus about to set and to the left of that is Auriga. Auriga will be easy to find since it is clearly marked by Venus. To the left of this you caan see the familiar constellation of Gemini, the Heavenly Twins with its bright stars Castor and Pollux. The image below shows the track of the comet.You can see that in May it is passing between the of Perseus and Auriga. Below is another view of the track of the comet courtesy of Astronomy Now. This gives you an idea of the scale. On the left is an outstretched spanned hand. Those of you who have attended my talks will know that this covers 20 degrees of sky. By contrast the full Moon only covers ½ degree of sky and can be covered by the little finger. To the right near Taurus you can see a blue circle marking the region covered by 10x50 binoculars. So if this is what you intend to use to find the comet you may need to scan around this region for quite a while before you find it. Finally, in the image below you can see what the comet looks like. I do hope you manage to see comet ATLAS and some of the planets I have mentioned. If you do, please let me know especially if you succeed in imaging anything.

Now to our friends in Dalian, China!

Dalian is at a latitude of 39° whereas we are at a latitude of 51°in England. This means that you will see much further into the southern hemisphere than we can. The latitude of Mallorca is also 39° so there they will see a sky very much like your sky in Dalian. But Dalian time is 8 hours ahead of GMT so you will see everything before we do but at about the same local time. The chart below shows the sky in the south over Dalian at 02:00 on May 31st. There you have the pleasure of seeing Saturn and Jupiter close to the wonderful Messier objects to be found in Sagittarius! The second chart below shows the sky in the south at 05:00 on the same day. There you can see that Jupiter and Saturn are joined by Mars and Neptune. The star chart below shows the Dalian sky in the north-west at 23:55 on May 17th. There you can see the constellation of Auriga which I have highlighted for you. This constellation can easily be found since Venus is nearby. Below Venus you can see Mercury which is just about to set. To the right of it you can see the constellation of Perseus. Above that is the faint constellation of Camelopardalis the Camel. Comet ATLAS will be tracking from Camelopardalis down between Auriga and Perseus as descibed in the first section of this Newsletter so there is a chance you will be able to see it.

Now on to the Southern hemisphere!

What's up in the Southern Hemisphere May, 2020 I would like to start this section of the Newsletter by showing the wonderful image below (courtesy of NASA and ESA). This was taken on April 24th to celebrate the 30th Anniversary of the . They have named the image “Cosmic Reef” and you can see an interesting video of it by going to https://www.youtube.com/watch?v=403-XMKwqk4 . The image shows the giant red nebula NGC 2014 amid a smaller blue nebula NGC 2020. Note that NGC means that they are listed in the . Both of these nebulae are clouds of gas and dust and are part of the (LMC), a satellite galaxy of the Milky Way. The LMC is about 163,000 light years away from us where a light year is 6,000,000,000,000 (6 trillion) miles. NGC 2014 is a shimmering collection of bright stars each about 10 to 20 times the mass of the Sun! NGC 2020 is a single star about 200,000 times the brightness of the Sun! The image was named “Cosmic Reef” since it resembles a coral reef shimmering in the corner of a deep ocean. The first star chart below shows the sky in the south over Sydney at 20:00 on May 1st and indicates where the LMC is located. In the middle left you can see the Southern Cross, Crux. Below that and slightly to the left you can see the bright pointer stars Alpha Centauri and Beta Centauri (also known as Hadar). To the right of Crux you can see the constellation of Carina the Keel. Below that is Volans the Flying Fish and to the right of that is Pictor the Painter's Easel. Below Pictor is the constellation of the Dolphin and below that you can see the location of the Large Magellanic Cloud, LMC labelled in red. Finally the second star chart below shows the sky in the east over Sydney at 22:00 on May 31st . There you can see Jupiter and Saturn rising. Above them is the constellation of Sagittarius showing the beautiful Messier objects which can be found in that region. To the left of this is the constellation of Ophiuchus which looks like the gable end of a house. That’s all for now. Until next month I hope you are able to enjoy some stargazing in spite of the current situation we are in! Stay safe and well!

Valerie Calderbank FRAS