Stars To See In The Sky Tonight

Here I give you the incredible facts behind some of the most interesting stars, and show you how pick them out for yourself in the sky tonight…

If you cast your eyes into the night sky tonight, all the stars are really just individual point sources of light of different subtle brightness and colours, and all inside our galaxy The Milky Way. Of course all together the stars in the sky make for a pretty fantastic skyscape, but there’s much more to those little points of light than meets the eye. Like in much of astronomy your imagination is valuable, you could never see up close the mind bending size of the red and blue supergiants, or get anywhere close to imagining just what the sunshine is like coming from a star 10,000 times more luminous than our Sun. The stars come in all different sizes, colours, brightness, temperatures, including some that look like one star but is in fact a system of two, or even four stars orbiting each other.

Based on view from UK, approximately 56 degrees north.


SiriusA and B artist's impression


That twinkling bright star that always catches your eye, flashing all different colours, red, green, blue. This star is Sirius and well known, also known as “The Dog Star” it is the brightest star in the sky. It lies to the lower left of that famous winter constellation Orion, in its constellation Canis Major. Sirius stands out in the winter and early spring sky twinkling and flashing different colours because its light is distorted as it passes through more thickness of the atmosphere, being a high luminous star so low down in the sky.

This distant sun is putting out the sunshine equivalent to 25 times that of ours, is twice as massive, and is 1.7 times the radius of the Sun. So when you look at the Dog Star in the night sky it looks like the one star, well of course it does. But this relatively nearby sun actually has company with it out in space. The Dog Star has a smaller stellar companion called, wait for it…”The Pup”.  The Dog Star known as Sirius A, and its smaller companion Sirius B (The Pup), are a binary star system orbiting every 51 years, with a distance from each other of roughly our Sun to Uranus. I said Sirius is relatively nearby, well yes in cosmic scales it is at a measly 8.6 light years distant, just down the road. The Sirius system qualifies as a neighbour to our own solar sytem, so the light you see from it has taken 8.6 years to cross space and reach you. The Sirius star system is fairly young at only 300 million years at its oldest, so it accomplished nuclear fusion as it formed out of its gas cloud at about the start of the Permian period on Earth. So of course this makes Sirius much younger than the Sun.

SiriusSirius B is a faint companion to the main star, and is a high mass white dwarf, almost equal to the Sun’s mass. This is pretty amazing actually considering that Sirius B has nearly the mass of the Sun all packed into a shining blue ball only the size of planet Earth…and you might know that the Sun is so big it could hold 1.3 million Earths in its volume. Sirius B was originally an even higher mass star than the highly visible Sirius A, but used up all its stellar fuel, bloated up into a red giant star, shed off its outer layers, and left behind the highly dense object astronomers observe today.

 Sirius is at magnitude -1.45

Coordinates for Sirius RA 6h, 45m, 42s / DEC -16, 43′, 51″

Where and when…

Sirius is visible briefly rising from the the south east just before sunrise in its constellation Canis Major, also seen in this map in relation to  Orion.


Betelgeuse artist's impression


If you look low to the south east during the small hours you’ll see the constellation of Orion rising, and a ticking time bomb 520 light years away. Marking the left shoulder of Orion the hunter is the red super giant star Betelgeuse. It stands out, as it’s definitely red looking, and bright.

It’s a colossal star at up to 1,000 times the diameter of the Sun, and shining in visible light a ridiculous 10,000 times brighter. It is violent and unpredictable, it swells and contracts, and sheds vast amounts of material into space in huge plumes.

This monster sun is coming near to the end of its lifetime, has evolved into a red supergiant, and is due to go supernova. Well, due doesn’t really mean next week, although it’s entirely possible, in astronomical terms due could be any time over the next 10,000 years, but Betelgeuse is going to blow that’s for sure.

Location of Betelgeuse

Location of Betelgeuse in Orion

A supernova is an unimaginably powerful event when the star collapses under its own weight after using up all its fuel. It tears itself apart exploding outwards seeding the cosmos with its elements to form new stars, planets, and maybe life…well it’s exactly how we got here. Supernovae are so bright they can outshine their host galaxy. If (when) Betelgeuse goes kaboom, you won’t have to wait till night time to view it, you’ll be able to see the supernova aftermath in broad daylight.

For a full article dedicated to Betelgeuse, go here “The Red Supergiant Star Betelgeuse”

 Betelgeuse is at magnitude 0.45

Coordinates for Betelgeuse RA 5h, 55m, 50s / DEC 7, 24′, 30″

Where and when…

During the early hours look low to the south east and you’ll see the constellation of Orion, with Betelgeuse marking its upper left shoulder. It then climbs slightly higher up to daybreak.




The star Arturus is a red giant, 25 times the diameter of the Sun, and travelling at some pace through the Galaxy. If you look at the unmistakable shape of the Plough, or The Big Dipper, whatever you prefer and imagine a line that follows the curve of the handle, you’ll come to a bright orange star 30 degrees from the Plough handle end star.

This is Arcturus, the brightest star in its constellation Bootes, and one of the brightest in the sky. Arcturus was originally a star not unlike the Sun but is further along in its lifetime, as it has now evolved into a red giant. Arcturus has swelled up to a bloated size as it comes to the end of its stellar fuel, and will eventually cast off its outer layers to become a planetary nebula, just as our Sun will do in a few billion years time. Arcturus is emitting about 110 times as much visible light as the Sun, but in infra-red it is even more powerful at around 200 times stronger. This stellar specimen 36.7 light years away is a few thousand degrees cooler than the Sun, and likely much older.

This star is moving at a rapid speed through the galaxy, and in a weird direction. It is travelling at a speed of 122 kilometres per second not in the general direction of all the rest of the stars, gas, and dust, but doing its own thing going perpendicular through the plane of the Milky Way. It has company too, Arcturus is one of about 50 other stars moving in the same way, in a stellar stream called the Arcturus Stream. Streams of stars like this are caused by gravitational tidal forces, stretching and pulling collections of stars from their original formation into long tendrils.

cLocation of Arcturus in Bootes, click to ENLARGE

Arcturus is at magnitude -0.04

Where and when…

To find Arcturus follow an imaginary curving line from the handle of the Plough, to a distance of 30 degrees from the handle end star (Alkaid). You’ll come to a bright orange star, this is Arcturus in Bootes

Tonight you’ll see this star fairly low in the west, it then sinks below the north western horizon by late evening.


Coordinates for Arcturus RA 14h, 16m, 14s /DEC 19, 07′, 24″





Main Capella system in infra red (Credit, the Cambridge Optical/Aperture
Synthesis Telescope)


Rising from the north after dark and climbing high in the east is the bright star Capella in Auriga. The constellation Auriga lies between Perseus and Gemini.

Capella is actually the sixth brightest star in the entire sky. Auriga is between constellations Orion and Perseus along the plane of the Milky Way. Look at Capella and yes it looks like your pretty normal, brighter than average star twinkling away. But all is not what it seems, Capella isn’t one, Capella is four, it is a star system of two binary pairs.

Capella’s clutch of four Suns come in two different flavours, a main pair of large G type stars measuring 12 solar radii…and a pair of faint, cooler red dwarfs. The main pair, and the red dwarfs make two binary pairs orbiting around each other. The main pair are in the same class of stars as our own Sun (G type), and orbit close to one another (100 million kilometres), whereas the red dwarfs lie some distance away. Quite far away in fact, the red dwarfs lie at around 10,000 astronomical units from the main stars, that’s 10,000 times the distance of the Earth from the Sun. Yes, space is big!

The main large pair each weigh in at roughly 2.7 times the mass of the Sun, and kick out 79 times more sunshine. They orbit each other once every 104 days, with about 100 million kilometres between them.

The second pair, being red dwarfs will have a mass of less than half that of the Sun’s. These smaller, cooler stars are the longest lived stars in the universe, so long lived in fact that the cosmos hasn’t even been in existance long enough for any to come to the end of their lives. So no red dwarf star has ever yet been observed to die, as they are slow burning, they really do take their sweet time. Red dwarfs can also emit as little as 1/10,000th the light of the Sun, so any planets in orbit around them need to huddle in close to warm any potential life there.

So there it is, the ‘star’ Capella in Auriga, 42.2 light years from Earth, and a little bit more to it than you might have first thought.

Location of Capella in Auriga, click to ENLARGE

Capella is at magnitude 0.05

Where and when…

Tonight look low to the north and you’ll see Capella rising after night fall. It stays on view all night, climbing high in the east

Coordinates for Capella RA 5h, 17m, 36s / DEC 46, 0′, 37″







Vega size comparison with the Sun


Look high to the south after dark and you’ll see the fifth brightest star in the sky Vega in constellation Lyra . It lies adjacent to the distinctive shape of the  swan of constellation Cygnus. Vega is one of the three bright stars that make up the summer triangle, together with Deneb in Cygnus, and Altair in Aquila. The summer triangle is an imaginary shape drawn between these stars against the celestial sphere, and is high up in the sky for northern latitudes during summer.

Compared to the Sun Vega is much, much younger at only one tenth the age of our own star. That makes Vega under 500 million years old, forming out of its gas cloud into a brand new star, just as complex life was starting to really get its act together on Earth. But Vega is not only younger than the Sun but has also 2.1 times more mass, meaning Vega will also die at a younger age. This is the fate of the larger higher mass stars, they have a brief and often violent life, going through their fuel at a quicker rate. In fact Vega is evolving so fast that it could already be nearing middle age, these heavier stars live fast and die young. Vega at 25.3 light years away is also bigger than our Sun, at over 2.7 times its radius.

All that is very interesting but Vega is doing something else, that you might not expect when you see it sitting there apparently unchanging and motionless in the sky. This star is spinning so fast it’s just under the point of breaking apart, it’s at 93% of that point. Just like how our very own Jupiter bulges out at the equator and squashes at the poles from its fast rotation, so it is the same for Vega. The equator of Vega is racing around at a speed of 274 kilometres per second, and the whole star rotates once on its axis every 12.5 hours. As you look up at the star in the night sky, you’re actually looking down onto its pole, so Vega’s axis of rotation is is pretty much pointing directly at you. This means that from your perspective on Earth if you could actually see it, you’d see Vega’s equatorial bulge.  It’s large at a massive 23% increased diameter across its equator, than its poles.

Location of Vega in Lyra, click to ENLARGE

Vega is at magnitude 0.00

Where and when…

Vega is in the constellation of Lyra high in the south after dark, staying on view all night until it moves lower to the north west by pre dawn.

Coordinates for Vega RA 18h, 37m, 21s / DEC 38, 47′, 43″




Mizar (and Alcor)

Mizar and Alcor


Look to Ursa Major tonight low in the north west after dark, and you’ll find the famous and easily recognisable asterism of the Plough, also known as the Big Dipper. The Plough is not the whole Ursa Major constellation (The Great Bear), but forms only a part of it. Also the seven stars of the Plough are not physically related to each other, but appear to be because of their similar brightness forming the well known shape.

Ok so as you’re looking up at the Plough, see the second star in from the end of the handle? That’s Mizar, at just over 78 light years away. But keep looking and you should see another less bright star pop into view next to it, that’s Alcor at just over 81 light years away…3 light years behind Mizar. So the star Mizar in the Plough handle is actually a double with Alcor. This easy naked eye double was thought to have once been used as a test for good eye sight. If you can see both stars then you’ve got pretty good vision, although spectacular eye sight is not required as most people can pick out both Mizar and Alcor quite easily.

But there’s more to these two stars, more stars in fact. If you look at Mizar through a telescope you’ll see that it itself is actually a binary double system. Bright Mizar has a nearby fainter companion star orbiting around it, Mizar A being the main star, and Mizar B its companion. Stay with me here, as it goes even deeper. Both Mizar A and also its fainter orbiting companion Mizar B even have their own companion stars orbiting around them as well. But these extra stars are so close that they appear as just the one star known as a spectroscopic double. But what about the other star in the main pair, Alcor? Well it was also found that Alcor has a companion, a star also orbiting so close that they just appear as the one, another spectroscopic double. So Mizar, the second star in the Plough handle is in fact really a double, double, double, six suns all gravitationally bound together in a sextuple system. The Mizar star sytem is one of only two six star systems in the whole sky, the other is Castor in the constellation Gemini.


Location of Mizar and Alcor in Ursa Major, click to ENLARGE

Mizar is at magnitude 2.2

Where and when…

Tonight as darkness falls you’ll see the Plough in the north west after dark. It then moves lower to the north and climbs higher in the north east up to daybreak.

Coordinates for Mizar RA 13h, 24m, 25s / DEC 54, 51′, 42″



Leave a comment below, or why not join the discussions on the Astronomy Central Forum

28 comments » Write a comment

  1. Just came across this site.
    I must congratulate you on an informative, easy to use and intuitive site. It’s simple to use but structured to inspire others to go out and look at the night sky. I’m just starting out in astronomy myself and find the site very helpful.
    Good luck with it and thanks!

  2. Hi Howard, sorry for the late reply.

    Thanks for the comments…enjoy your journey of discovery in astronomy.

  3. Hi guys just came across your web site found it really interesting going to delve deeper into what is up there cheers

  4. What a fabulous website I have stumbled across!! Very informative and easy to understand with lots of links to explanations. Who needs Brian Cox !!!LOL Can’t wait to get stargazing. Thanks for all your hard work.

  5. Hey John,

    Great website, thanks very much for providing all this information, a great help tonight! Helped me identify Mars, great stuff. Hope the clouds stay away for a while, might get a look at Saturn later!! A clear night for once here in Ireland!!

    Well done again,

  6. hi. i live in brighton and have a smallish back yard but is nice and dark so i have a good view of the night sky and it face’s north but i have a good view over the western sky and can see a lot of stars but can you tell me what planets can i see in august from the north west sky around the big dipper and cassiopeia. regards, andy.

  7. Hi if you can look very low to the south west right after dusk you can see Saturn with Mars below, in Libra. If you look north east/east before sunrise you can see Jupiter and Venus rising low in the sky. There’s no planets to the north or around the Big Dipper or Cassiopeia right now, hope that helps.

  8. Great articles!! Does Arcturus blink more than the others? I’ve been looking at the sky tonight and I think I’m looking at Arcturus by the position near the handle of the big dipper, but I don’t think I’ve ever seen a star blink as rapidly and noticeably change colors. At 11 pm CDT it is low on the WNW horizon, so, is it Arcturus?
    Thanks for all the information you share!

  9. Hi Silvia, if it’s bright and slightly orange in colour also, then yes it would have been Arcturus. When a bright star is low down to the horizon you are looking at it through more of Earth’s atmosphere than a star high in the sky. The atmosphere has pollution, heat and dust in it, this causes the light from the star to bounce around, flicker, and change colours.

  10. Thanks for the information, looking out at stars in new jersey and wondered what they were all about. Thanks for posting. Great article, love stargazing.

  11. Hi, I am from bangalore (india), tonight at 2:05 AM I saw something twinkling sky in red & light yellow colour for more than 5 min. I didn’t understand what was that.

  12. Wow thanks so much for this, I was looking originally for something flashing blue white possibly red… I thought I was going mad… but it’s the Dog Star it would seem… I’m not insane! Will you be putting up information tomorrow about the spectacular stellar performance we’re due to be expecting…?
    I look forward to reading what you’ve to say, if this is anything to go by. A fabulously informative page. Thank you very much, astronomy made easy! 😀

  13. Just read your very clear information about the dog star and relayed it to my kids whilst staring out of their bedroom window! Enthusiastic amateurs! Thanks Chris

  14. Great site! The Dog Star lead me here. I wanted to find an article on that bright flickering multi-coloured star I kept seeing in London’s night sky; but I kept on coming across “UFO sightings” articles. My boyfriend was convinced it was man made or a satellite. Very informative and helpful. This is some Sirius stuff! 😉


  15. Really enjoyed your wirte up. I am an ex Navigator Wireless in WW2 and later a Nav
    with an airline. Became a pilot when INS displaced us. As a nav., we had friendly stars and
    planets with Sirus being the one I liked best.

    • Hi Phil, Yes I’ve heard pilots use the stars and planets to know where they are, friendly stars is a great term. Sirius is unmistakable, stays low and flashes different colours.

  16. for the past few months i have noticed a big star in the eastern sky that is like 3 times bigger than the north star, and for years i have always thought the north star is the biggest. is there a reason why there is a star in the sky bigger than the north star, which also looks like its getting bigger as months pass

  17. hello robbie, have you had a reply to the BIG STar question yet. I’ve just been out (in Brighton) and have seen this HUGE white star and am wondering what it is?!? I reckon it is somewhat south east of ursa major

  18. I am at yew tree lodge looking towards calcot and their I saw a white light it seemed to stay infront of the clouds . and shine rather white if it is infront of the clouds that would say it is not a planet does it or not

  19. I am a new sky watcher and really today i found this is really easy and helpful to find intresting things.Please me more tofind out good stars.


  20. It won’t necessarily cost less to get your site this way, but it does provide a way
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  21. Today(12-8-2015) I saw a bright star like object twinkling enormously at about 10:00 PM. It was not behaving like a normal star but was very bright and twinkled very fast.
    In West/north-west can anybody let me know what was that

  22. I just saw a star tonight from my window I hadn’t noticed before. It is the first time I notice a star twinkling in multiple colors (blue, red and white). At first I thought it was an LED light because it was just above the roof of a building. Googling led me to this site, and it seems like it could be Sirius, from what is described about its position. So thanks for the post!

  23. Thanks for the information you provide! I had wondered for years what caused Sirius to flash different colors, heck I just learned it was called Sirius. Anyways, I remember being told at one time that it was 2 different colored stars rotating around each other at very high speed.
    I recently moved way out in the country and have such a sky full of lights that I will be using this site often as the skies get really clear here in the winter. This morning before sunrise the moon,Venus,Mars and Jupiter were really spectacular. I may even buy a real telescope instead of using the scopes on my rifles and my spotting scope.
    Again…..Thank You hmj

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