Recognizing the Constellations
completedRecognizing the ConstellationsRecognizing the Constellations
Today, we use the constellations to divide the sky into small areas so that stars may be more easily designated. The International Astronomical Union divided the entire sky into eighty-eight standardized constellations in 1928.
Many students find it very difficult to learn the shapes of the constellations and to recognize them in the night sky. Some students find it easier to learn the many constellations in two groups. The first group is easy to recognize because of bright stars or a distinctive pattern. You can recognize the second group by its association with members of the first group. For example, some people find the constellation of Draco to be very faint and indistinct. It is fairly easy to locate if you associate its position with the more easily identified constellations of Ursa Major (Big Dipper) and Ursa Minor (Little Dipper). Do not be disappointed if you cannot learn all these constellations in a single evening. It will probably take several weeks of study for you to feel comfortable with the constellations. I realize that for many of you this is all a new experience. I find figures 2-6, 2-7, and 2-8 on pages 25–26 of the textbook to be particularly helpful in getting oriented, depending on the season in which you are observing. For those of you in the Southern Hemisphere, these are not much help. However, I had to make a decision to go with the constellations that can be viewed by the vast majority of students in this class.
When you go outside to learn the constellations, you will have a greater success rate if you make some careful preparations. Be sure you know the directions outside (north, south, east, and west) so you can properly orientate your star maps.
Make copies that you can take outside and ruin. You can print and use the maps included here, or make copies of the maps in the textbook for this course.
- Printable Star Map 1 (Winter Triangle)
- Printable Star Map 2 (Summer Triangle)
- Printable Star Map 3 (Polar View)
Many times it will be helpful to take a flashlight to help you with reading the maps. A piece of red cellophane taped over the flashlight lens will help to preserve your night vision. This is because the pupil of your eye will not contract as quickly when exposed to long-wavelength red light. Also, make sure you are dressed comfortably for the season in which you will be observing. This will help you avoid the annoying distraction of being either too hot or too cold. Finally, if at all possible, choose a site with a dark sky to do your observations. In many cities it is not possible to see the stars of Ursa Minor because of the brightness of the night sky.
Note that all of the stars and constellations are not visible during a single season. Therefore, you will have to find the ones visible during the season you begin this class. Be content to learn the others from the maps and then try to locate them in the sky during the appropriate season. The electronic star maps are useful for these “off-season” constellations.
Students living in the Southern Hemisphere will not be able to see most of the northern constellations. These students should learn the far-north constellations from the star maps, the textbook, or from an online source. Some constellations (such as Leo, Virgo, Orion, and so on) are visible from southern latitudes. You should try to find these in the sky during the appropriate season.
In this course, and especially in preparation for the constellation quiz, in addition to the constellations of the zodiac, you should work to learn the following eighteen constellations and be able to recognize them in the sky:
| Eighteen Constellations | |
|---|---|
| Andromeda | Corona Borealis |
| Aquila | Draco |
| Auriga | Hercules |
| Boötes | Lyra |
| Canis Major | Orion |
| Canis Minor | Pegasus |
| Cassiopeia | Perseus |
| Cepheus | Ursa Major |
| Cygnus | Ursa Minor |
Also be forewarned that you will be required to be able to recognize and associate the following 16 bright stars with the constellation to which they belong when you take the constellation quiz:
| 16 Bright Stars | ||
|---|---|---|
| Aldebaran | Castor | Rigel |
| Altair | Deneb | Sirius |
| Antares | Polaris | Spica |
| Arcturus | Pollux | Vega |
| Betelgeuse | Procyon | |
| Capella | Regulus |
You can more easily recognize some of the constellations if you use some of the stars to form simple patterns. Below is a list of some of the constellations and the shapes associated with them.
| Constellation | Pattern |
|---|---|
| Auriga | Pentagon |
| Boötes | Kite or ice cream cone |
| Cassiopeia | W or M |
| Cygnus | Northern Cross |
| Hercules | Bow tie or keystone |
| Leo | Sickle |
| Pegasus | Great square |
| Sagittarius | Teapot |
| Ursa Major | Big Dipper |
| Ursa Minor | Little Dipper |
You can also find several prominent star clusters in the sky. The Pleiades and the Hyades clusters can be seen without optical aid. Most students do not realize how many objects can be observed with the aid of binoculars. The night sky contains dozens of star clusters that require only binoculars and a little patience to locate.
The list that follows contains several prominent star clusters and the constellation to which they belong:
| Cluster | Constellation |
|---|---|
| Pleiades | Taurus |
| Hyades | Taurus |
| Praesepe | Cancer |
| Double Cluster | Perseus |
| M13 | Hercules |
| Coma | Coma Berenices |
The next list gives some of the more prominent non-stellar objects visible in the sky, along with the constellation in which you can find them. Many of these objects are faint and are not visible without the aid of binoculars or a small telescope.
| Object | Constellation |
|---|---|
| Crab Nebula | Taurus |
| Andromeda Galaxy | Andromeda |
| Orion Nebula | Orion |
| Horsehead Nebula | Orion |
| Ring Nebula | Lyra |
Some people form bright stars from different constellations into easily recognizable patterns. Two of these patterns are in the form of triangles. These are shown in the textbook as figures 2-7 and 2-8. These are especially helpful in familiarizing you with large areas of both the summer and winter skies. These triangles are discussed on pages 25 and 26 of the textbook. The first triangle is formed from the three stars Betelgeuse, Sirius, and Procyon (see figure 2-7 in the textbook). This triangle is very prominent during the winter months and is therefore known as the Winter Triangle. The second triangle is made by drawing an imaginary line between the stars Vega, Deneb, and Altair (see figure 2-8 in the textbook). This group of stars is very prominent in the late spring and summertime sky. For this reason, this group of three stars is sometimes called the Summer Triangle. These are just two of the many possibilities for geometric figures that can be made using bright first-magnitude stars.
If you are successful in familiarizing yourself with the night sky, you should be familiar with all of these constellations, stars, clusters, and non-stellar objects. I know it seems overwhelming at the start of the course, but with a little practice you’ll be surprised how easy it is to recall these objects.