Some of my earliest stargazing memories involve the same seven stars. Whether you call it the Plough or the Big Dipper – or even the saucepan, the panhandle or the wagon – the stars that form this asterism are ones I think many people learn to recognise from an early age. But just because most people can recognise the Plough, and, by extension, Ursa Major, the constellation in which it lies, doesn’t mean we have explored everything in this patch of the sky. And May is as good a time as any to get to know the Great Bear.
Ursa Major is a circumpolar constellation in the northern hemisphere, which means it never sets and is visible to stargazers year-round in northern-enough latitudes.
Parts of Ursa Major, including the bear’s legs, can be seen from some locations in the southern hemisphere. But the Plough is not visible from Australia.
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Somewhat confusingly, there is another “saucepan” star pattern, or asterism, visible in Australia, sometimes referred to as the little dipper, comprising stars within the constellation Orion. Its handle is the three stars of Orion’s belt.
Finding the Plough (pictured)starts with looking north to find the four stars that make up the “pan” part of the asterism, and the three bright stars that extend behind it, which are the “handle” of the pan. This handle is the tail of the bear, and it extends from a star in the upper corner of the pan, called Megrez.
Once you have the Plough, identify the rest of the bear by looking out from the other three corners of the pan. Look for the star in the lower corner closest to where the tail comes out, called Phecda, from which the back legs extend. Follow the stars in an anticlockwise direction and you will reach the star from which the front legs extend, called Merak, followed by Dubhe in the upper corner, from which the bear’s face and its long torso appear. You might know this pair already, as Merak and Dubhe point towards the north star, Polaris.
One challenge, once you know your way around Ursa Major, is to find the Owl Nebula. This is a planetary nebula. These have nothing to do with planets, but they were named that way because they look like a ring around a planet. They are created by the death of a large star, which released gases that ended up as a cocoon around it. The Owl Nebula, also known as NGC 3587, sits just to the south-east of Merak. To see its owl-eye shape you will need a large telescope, but it can also be spotted with binoculars, looking like a fuzzy dot.
The Owl Nebula isn’t visible from the southern hemisphere, but stargazers in the south this time of year could instead look for planetary nebula NGC 3132, also known as the Eight Burst Nebula, in the constellation Vela. It sits between the bright star Canopus and the long constellation Hydra.
Abigail Beall is a features editor at Â鶹´«Ă˝ and author of The Art of Urban Astronomy. Follow her @abbybeall
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