Astronomy at a distance: Constellations
This week we look at some of the most recognisable features in the night sky - the constellations. Constellation is a word that comes from ancient Latin, meaning ‘the coming together of stars’. They’re the regular patterns that we can see in the sky, formed by some of the brightest stars. They are constant but change their position with the seasons. You can use them to navigate and many ancient cultures have looked up at them. Patrick Cronin-Coltsmann, a PhD student from Warwick’s astrophysics team, takes us through some of the easiest to spot.
First you’ll need to get your bearings. We’ll be guiding you in part by the Cardinal Directions, - North, East, South and West.
If you are facing North, then East is to your right, West is to your left and South is behind you. ‘Due North’ just means ‘nearly-exactly North’. To find North you can use a compass or a compass app on a smartphone. You can also remember where the sun set. At this time of year, in the Northern Hemisphere, this is very close to due West.
Another way is to find the North Star, Polaris. Polaris lies at due North in the sky, and because of its location it does not appear to rotate with the rest of the sky during the night, in fact it appears as though all the other stars are spinning around it. If you have already managed to find The Big Dipper/The Plough, imagine the handle of The Big Dipper to be at the top-left corner of its bowl. You can then find Polaris by following a straight line from the bottom-right corner of the bowl to the top-right corner and beyond until you reach the next brightest star. This star should lie at the tip of the handle of The Little Dipper, another constellation that looks very similar to the Big Dipper, but is smaller and flipped upside down. This star at the tip of The Little Dipper’s handle is Polaris.
Here are some of the constellations that you can pick out in the night sky in the UK at the moment if you were to go outside at around 8-9pm:
- The Big Dipper: Also known as The Plough, this is one of the most well-known sights in the sky and is named for its shape: four bright stars make up a bowl and three bright stars make up a handle. The Plough is actually part of a bigger constellation called Ursa Major, ‘The Great Bear’. The Plough makes up the bear’s hindquarters and tail. Find The Plough high in the North-East sky, and see if you can spot the rest of Ursa Major.
- Another famous constellation is Orion. The Greeks saw Orion as a mighty hunter holding up a shield in front of him and raising a club behind him. One of the most stand out features of Orion is the three bright stars in a straight line which form a belt across his waist. Look out for the red giant star Betelgeuse in his shoulder, it’s one of the brightest stars in the sky and its red colour is plain to see. You can find this constellation a little bit above the horizon in the South-West sky.
- A much simpler constellation is Cassiopeia. Cassiopeia was named for a beautiful but boastful queen, although this constellation is more recognisable as a bright ‘W’ formed by five stars. Look for the ‘W’ a little above the horizon in the North-West sky.
- Our next constellation contains the brightest star in the night sky, Sirius. Sirius forms the top-right corner of the constellation Canis Major, ‘The Great Dog’. You should be able to make out the front and hind legs of Canis Major as well as its tail. Look just above the horizon between South and South-West for a bright star, if you find Sirius, you’ve found Canis Major. See if you can make out its body.
- Our final constellation is Taurus, ‘The Bull’. Six stars form a small head with the red star Aldebaran in one eye and three stars make two long horns pointing up. Also, a single star stretches to the East to form the body. The star that forms the body lies right next to an amazing cluster of bright blue stars called the Pleiades, and you might also spot the planet Venus which is also very nearby. Venus is the brightest point in the sky right now, so it should be readily visible above the horizon towards due West. Find Venus, and both Taurus and the Pleiades will be nearby. The head of Taurus can be found about halfway between the Pleiades and Orion’s shield.
Can you find everything on this list? If you’re having trouble, make sure you've given your eyes time to adapt to the dark.
9 April 2020
The Astronomy and Astrophysics group at Warwick is interested in a huge range of scales across the Universe: planetary systems, how they form, live and die; stars, stellar binaries and and the exotic physical processes that they allow us to explore; as well as the transient events which mark the end of stellar lifetimes and the galaxies stars inhabit across the Universe. The group started in September 2003 and is both an observational and theoretical group. The group makes use of a wide range of ground-based telescopes, such as ESO's Very Large Telescope (VLT) in Chile and the Isaac Newton Group of telescopes (ING) in the Canary Islands, or the Atacama Large Millimetre Array (ALMA), as well as space telescopes such as NASA's Chandra and ESA's XMM-Newton X-ray observatories and the Hubble Space Telescope. The Warwick astro group partners in the four large spectroscopic surveys (DESI, SDSS-V, WEAVE, and 4MOST) that will start operations throughout 2020-2021.
Terms for republishing
The text in this article is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).