We’re starting a new feature for those members new to astronomy. This month to start you off we have “Getting started in astronomy”, a guide to those “first steps” in astronomy and a view of some key constellations of the northern skies. Plus “Constellation of the month”, a closer view at Andromeda this month.
Stars appear to be scattered across the sky and how can you ever make any sense of them. And
which ones are planets, how do you find them. In the northern skies there are about 2,000 stars viewable up there with your naked eyes. But most of us may be able to see 200 maximum due to town light pollution blotting out the fainter stars.
The first things to think about are where shall I observe and what do I need to take outside with me.
Find somewhere safe and away from street lights directly shining on you. If you can find a safe site away from street light that is even better. Back gardens are a good starting place. Do go outside and don’t just look through windows. Give you eyes 15-20 minutes and you’ll begin seeing a lot more. You’ll need to keep warm and comfortable so anything from warm clothes to a comfy outside chair or even deckchair could be used.
You don’t need heavy expensive equipment just a planisphere, ( check Phillips Planisphere at
Amazon.co.uk) decent astronomy book (Collins Gem Night Sky) and a pair of binoculars (10×50 are ideal). You’ll also find that decent stores such as Waterstones will stock Planispheres and Collins Night sky book.
Scale in the sky: A fist held out at arm’s length is a convenient measure of angular size in the sky.
Here a fist is shown in comparison with the seven stars of the Plough (or Big Dipper) in Ursa Major.
I’m going to assume you know how to locate the Plough (above). This is a great starting point for your night of star gazing. The plough is a part of the constellation of Ursa Major but is easy to find and is a great signpost looking north. We measure the distance between stars as we see them from Earth in degrees, minutes and seconds. More of that later.
Using the Plough as a signpost
Now let’s use the various signposts of the Plough to help you move to other constellations. Look for the 2 pointer starts that will take you to the North Star, Polaris and onwards to Cassiopeia. Going in the opposite direction takes you to the constellation of Leo and the backwards question mark, “The Sickle”. Back to the Plough and follow the handle of the Plough and “arc” to the star Arcturus in
the constellation of Bootes. Continuing past takes you to Spica which is the brightest star in Virgo.
Use your planisphere to look around the main stars and find Andromeda, near Cassiopeia, maybe even find M31 with your binoculars. Don’t forget to look at your Night Sky book too.
Using your hand to gauge distance in degrees
By using your hand you can gauge the distance in degrees between objects. Your fist held out at arms length measures about 10 degrees. Also at arms length the width of your index finger is 1 degree and the middle 3 fingers together is about 5 degrees.
Click here for Part 2 of this article