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What's Up for August 2015

It's August and holiday time.  With luck you'll be able to get away to place with a darker sky than you're used to, or at least stay up a bit to make the most of whatever you've got. And at least you won't get frostbite. But how do you make sense of all those stars?

That's where we come in. Use our easy-to-follow sky guide and you'll be out there stargazing in no time. You will need a star map, and you will need to know how it works. This may seem obvious, but there is a knack to understanding these things. Here's our map for this month:

Sky for August 15

Wrong way round?

Now don't write in and tell us that we have the points of the compass all wrong. This is a map of the sky, so you have to hold it over your head. When you do this, east and west will be the right way round.

It shows the whole sky, so the scale is quite small. Normally you turn to see different parts of it, so to see the view looking north, for example, hold the map upside down with north at the bottom.

The map shows the sky in mid August at about 10.30 pm, at the start of the month at 11.30 pm, or by the end of the month at 9.30 pm. All times are BST.
 

TIP If you aren't sure of the direction of north from your location, click here for a page on Getting Your Bearings.

Making sense of the stars

This being summer, the best way to find your way around the sky is to use the Summer Triangle. Actually this is not as obvious as it seems, because this triangle still remains visible well into the autumn and even the winter, but the fact is that it's a key feature of the summer skies so we might as well stick with the name.

Find it by looking right overhead to find a really bright white star, Vega. It's the only bright star close to being overhead, so ignore all other stars and look really high up. The next star of the triangle, Altair, is halfway between Vega and the horizon. Altair has a fainter star on either side of it – look at the map to get the idea. The other star is Deneb, which is a bit lower down towards the eastern horizon than Vega. If you can't spot these three stars straight away, remember that the map above is on quite a small scale, so think big and you should spot it.

Many people recognise The Plough, which if you want to get your bearings is over in the northwest. We've picked it out on the map. If you think of the Plough as a saucepan, then follow its handle round towards the horizon, you come to a bright star called Arcturus, which is about the same brightness as Vega but low down in the western sky. It's also slightly yellowish, and if you thought all stars were white, compare it with Vega to see the difference.

Now use the map below to find more patterns nearby, but don't expect to see those convenient lines helping you to see the patterns. If you do see them, consult an optician or give back those glasses your friends gave you on 1 April.

Map for August 14 with constellation namesAll maps produced using Stellarium software.

Other constellations to look for

Once you have found the Summer Triangle, you can now start to look for some constellations. There's Cygnus, the Swan, also known as the Northern Cross. It is a large cross-shape with Deneb at the top, marking the tail of the swan which flies down the Milky Way with outstretched wings. Fair point. You live in Neasden or Newcastle and can't see this Milky Way which is shown on the map. You'll just have to take our word for it that it's there.

To find out more about Cygnus, including why it is unsuitable for children, click here.  One of the best-known stars in Cygnus is Albireo, a fairly faint star marking the head of the Swan, or the foot of the Cross.  Midway between Altair and Albireo is a rather cute constellation called Sagitta, which means Arrow. Use this to find some other interesting objects, and the constellation of Vulpecula, by clicking here.

This is the time of year to look way down on the southern horizon for the constellation Sagittarius, which form a sort of teapot shape, But unless you have a good, clear night and are well away from city lights, you might not see the stars at all well.

There are plenty of nebulae and clusters visible with binoculars in this part of the sky, so check out our guide to them.

To the left of Vega is Hercules, whose most obvious feature is a parallelogram of stars called the Keystone, though it isn't particularly bright.

The map shows the Milky Way as a pale band crossing the sky. This is a good time of year to look for it, though you won't see it from light-polluted areas. The best chance of seeing it is high up in Cygnus, but if you go on holiday to a dark-sky area it can appear so bright you will wonder why you can't see it at home.

If you want a map with all the constellation names on it, click here.

The month's planets 

The only planet on our map this month is Saturn, and you have to be quick to see it at all. It's over in the west, quite low, and the best time to see it is a bit earlier than our map time, as soon as it starts to get quite dark, and sets soon after dusk. If you have a telescope you can see the rings of Saturn but with it being so low in the sky they will probably not be very distinct.

Mars is in the morning sky, rising about 4 am BST over in the northeast just before the Sun. Mercury, Venus and Jupiter are too close to the Sun to be seen.

Where’s the Moon, then?

It begins the month just after new Moon, which was on 26 July, so it is a fat crescent on the first few evenings of the month.  Then first quarter (the evening half Moon) is on the 4th. Full Moon is on the 10th so not much observing of faint objects will be possible then. Finally, last quarter is on the 17th and we have new Moon again on the 25th. Sorry, no eclipses this month.
Perseid meteors
Two Perseid meteors.
Pic: Robin Scagell

We have a whole section of the website devoted to the Moon and its features.

August’s shooting stars

August is usually a great month for shooting stars – what astronomers call meteors. You can expect one every ten minutes or so on most nights, as long as you have a fairly dark sky. Around Tuesday, 12 August we get the annual Perseid meteors, which are one of the year's strongest showers, but this year the Moon is just after full and will make the sky rather too bright for us to get a good view. But it might be worth watching in any case, if it's is really clear.

The Perseids don't just appear in Perseus (which is shown on our map at the top) but can appear anywhere in the sky. They appear to come from the direction of Perseus in the northeast. You may hear that there could be 80 an hour visible, but don't take that too seriously. That's a theoretical number based on perfect conditions, which won't apply. You might see one every few minutes, though there are sometimes bursts of activity with a few in a single minute. The Moon will make them more difficult to see.

You can find out a lot more about what to do when you see one in our guide to observing meteors. And there's a 35-minute video from our Meteor Section Director telling you all you need to know about observing the Perseid meteors.

Get more helpful info

OK, you've read all this for nothing, now comes the plug. This page is brought to you by the Society for Popular Astronomy, which is a really great society to join. It's based in the UK but there are members in other countries as well. It doesn't cost much to join, and there is a special rate for Young Stargazers. At least take a look at what we have to offer. 

 

Text by Robin ScagellText by Robin Scagell