Learning The Night Sky
I had the opportunity to get out to a dark sky site recently for some much needed deep sky observing so I packed up my gear and made the hour and a half drive to Nirvana. When I arrived at the site I was greeted by members of the astronomy club I belong to, and 10 members of two other area clubs. I guess great minds do think alike. Anyway, I didn’t waste any time setting up my scope. For this night I choose my 150mm refractor and my go-to EQ-G mount. As usual there were many different sizes and types of telescopes present, classic Newtonian’s, refractors, SCT’s and those large truss Dobsonian telescopes that seem to be cropping up all over. 18” and 22” telescopes that take an hour or more to setup. I was setup and ready to observe in less than 15 minutes. Once the sun set and Polaris was visible it took me another 5 minutes to polar align the mount, zero in on a couple bright stars and I’m ready to go. I don’t dislike the big scopes and I certainly enjoy the great views they give. I just don’t want anything that big to haul around.
Now, maybe I’m a little old school but, I always thought that part of the hobby of backyard astronomy is to learn the night sky. Just the basics like the constellations and a few names of the brightest stars and being able to track down deep sky objects with my finder scope. I think us old timers call it star-hopping. Now, imagine driving for an hour and a half, spending another hour to setup your scope, only to find out the go-to isn’t working. Does that mean you can’t use your telescope? For one gentleman it did. He setup his Big 22” Dobsonian only to find out his go-to wasn’t working. “That’s it for me” he said. “I’m lost without my go-to”. No way pal. If my go-to fails or my power supply is dead, I’ll just find my targets by star-hopping. Seems to me that many amateur astronomers today don’t know how to star-hop to their targets. Go figure.
Don’t get me wrong here; I like the go-to features as much as the next person but, you really should know your way around the night sky. At least enough to know how to find the brighter deep sky objects. So, how does one go about learning their way around the night sky? It’s much easier than you think. Grab a Planisphere and a red flash light and go outside and learn the constellations. The Planisphere makes it easy because you just rotate the wheel to match your time and date to your location. All the constellations showing on the Planisphere will be visible in your night sky. After a few nights’ you’ll be picking out constellations like an old pro. While you’re at it, learn the names of a few of the brightest stars. It will help you pin things down a little better. If you don’t own a Planisphere and want to get started right away, you can download and print a monthly chart for free at SkyMaps.com or make your own by downloading the one by Dominic Ford. Visit his website at In-The-Sky.org.
In the northern hemisphere, most people in the U.S. can recognize the Big Dipper (in Europe it’s called “The Plough”). That’s a good starting point. The Big Dipper is of course just a small part of a larger constellation called Ursa Major, the Big Bear. See if you can trace out the whole constellation. Two stars to become familiar with are the stars at the front of the Big Dippers bowl, Dubhe (alpha UMa) and Merak (beta UMa). Start at Merak and draw a line to Dubhe and continue that line until you come to Polaris, The North Star. Many people think the North Star is the brightest star in the sky, but that’s not true. Sirius is the brightest star in the night sky, but don’t worry about that right now, we’ll get to it later. For now, just locate Polaris. The reason Polaris is so well known is the fact that it circles the North Pole. Polaris is used as a navigational star by ships at sea and has been for many centuries. Polaris is also the last star in the handle of the Little Dipper, which is part of the constellation Ursa Minor or the Little Bear. If you’re at a very dark location, you may be able to trace out the faint stars of the Little Dipper. Now, go back to the Big Dipper and notice how the handle arcs. Starting at the back of the Big Dippers bowl, connect the stars of the handle and continue the arcing motion until you come to another bright star. That’s Arcturus (alpha Boötis). A mnemonic for this is “Arc to Arcturus”. Arcturus is the brightest star in the constellation Boötis, the Herdsman. The constellation Boötis looks somewhat like a kite. See if you can trace out the whole constellation.
Learning the constellations and the names of the brightest stars is a fun and rewarding part of backyard astronomy. It’s also a great family activity. Take the family out while the Sun is setting and watch the sky as the brightest stars begin to shine. See who can be the first one to see Polaris, the North Star or the stars of the Big Dipper or even Arcturus.