Tips for Locating Stars and Constellations

by Ken Wilson

One of the great rites of passage for an amateur astronomer is learning to recognize the major stars and constellations. Since one can locate celestial objects quite simply via setting circles, many advanced amateurs and even some professional astronomers are familiar with only a very few constellations. Beyond their usefulness in finding celestial objects, a knowledge of the constellations is of great aesthetic value. There is history, horror, romance and adventure in the abundant celestial mythologies. And, being able to look up at the stars at any time of night or year and know their names, is a source of great personal satisfaction.

It might seem a fairly simple matter to pick out and remember the basic constellations. After all, there are only 88 of them all together; they are all well mapped; and, you don't need a telescope to find them. There are, however, a couple of complicating factors. First of all, they just won't stand still. Every minute, hour, day and season they seem to move, due to the earth's rotation and revolution. In addition, most constellations don't look at all like their namesakes.

But, all is not hopeless for the would-be constellation gazer. Lacking a computer, the best way to locate unfamiliar constellations is by using the ones you know as stepping stones to them. There are a few tricks of the trade that will be of some help. The following list of tricks was prepared several years ago by Doris N. McMillan (formerly of the Cranbrook Institute of Science). I have taken the liberty of revising and expanding on this excellent list

Year Round Circumpolar Constellations

1. Let's begin with the most well known star pattern, the Big Dipper. From most of the Northern Hemisphere, this group of seven stars is always found in the northern sky. Actually, the Big Dipper is not a constellation, but only an asterism (a well known part of a constellation). The Big Dipper's stars form the hind quarters and tail of Ursa Major (the Big Bear) which is an official constellation.
2. Take the two stars that form the front of the bowl of the Big Dipper and draw a line through them in the direction away from the bottom of the bowl. This line will always point to Polaris, the North Star. Polaris is at the tip of the handle of the Little Dipper. And, like the Big Dipper, the Little Dipper is also a part of a bear/constellation, Ursa Minor (the Little Bear).
3. Along the line from the Big Dipper's pointers to the North Star (about one third the distance to the North Star) look for a star that represents the tip of the tail of Draco (the Dragon). The Dragon's tail winds between the two bears, curving back behind the Little Bear. It then turns around again, ending in a trapezoid of four stars representing the Dragon's head.
4. Draw a line from the middle star of the Big Dipper's handle through the North Star. This line will lead to a "W" shaped group of stars called Cassiopeia (the Queen of Ethiopia). Along side her can be found her husband, King Cepheus. He's shaped like a box and triangle house that a young child might draw.
   

Spring Constellations

5. Draw another line through the Big Dipper's pointers, but this time in the direction away from the North Star. This line will lead to the brightest star in the constellation Leo (the Lion). This star is called Regulus and appears to be the period at the bottom of a "backwards question mark" pattern of stars which represents the head of the Lion. A triangle of stars to the east represents the hindquarters and tail of the Lion.
6. The handle of the Big Dipper is bent into an arc. Follow the projection to this arc, and it will lead you to the bright star Arcturus ("follow the arc to Arcturus"). Arcturus is at the bottom of a kite-shaped constellation called Bootes (the Herdsman). Bootes can also be thought of as a celestial ice cream cone, with Arcturus on the bottom at the peak of the cone. Along side the ice cream cone is semicircle of stars that could represent a second scoop of ice cream that might have fallen off the cone. This second scoop of ice cream is actually a separate constellation called Corona Borealis (the Northern Crown).
7. Now, continue the line through the pointers further south to another bright star called Spica, in the constellation Virgo (the Virgin). The prominent stars of Virgo form a distorted "Y" configuration.

Summer Constellations

8. Go back to the Dragon and relocate the four stars of his head. Nearby will be found a bright, blue-white star called Vega. Vega and a parallelogram of four fainter stars are the principle stars of Lyra (the Lyre).
9. Southeast of Lyra is a cross-shaped constellation called Cygnus (the Swan). The bright star at the top of the cross is known as Deneb.
10. South of Deneb and Vega is another bright star called Altair. Deneb, Vega and Altair form an asterism called the Summer Triangle. Altair is the brightest star in the constellation Aquila (the Eagle) which is shaped like a large, ragged "T".

Fall Constellations

11. 11. On the opposite side of Cassiopeia from her husband King Cepheus, look for an almost straight line of three bright stars, much farther apart than the stars of Orion's belt. These are the brightest stars of the constellation Andromeda (the Princess).
12. 12. At one end of the line of stars of Andromeda there are four stars in the arrangement of a square that represent the body of Pegasus (the Flying Horse).
13. 13. At the other end of Andromeda is a distorted "K" shaped constellation called Perseus (the Prince).

Winter Constellations

14. Orion (the Hunter), a winter constellation, is very easy to recognize because of the many bright stars that it contains. Two of these stars, Betelgeuse (the brightest one in Orion and reddish in color) and Bellatrix form Orion's shoulders. Two other stars, Rigel and Saiph form Orion's legs. A short row of three dimmer stars in the middle of Orion marks his belt. These seven stars give Orion an overall shape of an hourglass, or a bow tie on its side. Orion usually dominates the southern sky in winter.
15. Draw a line through Orion's belt and extend it southeast. It will lead to one of the brightest stars in the sky, Sirius (the Dog Star) in the constellation Canis Major (the Big Dog). Canis Major resembles a slanted "T" with two, short stubby legs attached to it.
16. Draw the line through Orion's belt again, but in the opposite direction to find the star Aldebaran, the bright red eye of Taurus (the Bull). The face and horns of the Bull are marked by a long, "V" shaped group of stars that stretch up over Orion. In the shoulder of the Bull will be found a cluster of six or seven stars that are known as the Pleiades, or Seven Sisters.
17. North of Orion will be found a pentagon of stars which mark the constellation Auriga (the Charioteer). The bright star in this group is called Capella (the Goat Star).
18. Take Sirius and Betelgeuse and look for another bright star northeast of them that completes an equilateral triangle (an asterism called the Winter Triangle). This star is called Procyon (the Little Dog Star) in the constellation of Canis Minor (the Little Dog).
19. Northeast of the Winter Triangle are two, almost identical (twin) stars, called Castor and Pollux (Pollux is actually a little brighter than Castor). These two stars lie at the top of a rectangular shaped constellation called Gemini (the Twins).

Please note that, due to the glare of poorly designed outdoor lighting in the city and suburbs, it may not be possible to see all of the stars and constellations above from an urban environment. Glare from the moon when near its full phase may also interfere. If you can't find some of the groups from your backyard, try observing from a darker location far away from the glare of the city. Also, allow your eyes at least 20 minutes in dark surroundings to adapt to the darkness. This 'dark adaptation' will allow your eyes to function at maximum sensitivity.

By the time you learn to use all of these tricks, you should be able to use a star chart to locate anything that you want to find in the sky.