As Autumn approaches later this month, we get to see in the early evening sky what some would call ‘Deep Space’. Through most of summer the Milky Way has captured our attention and shown us a view of objects inside our home galaxy that range in the tens, hundreds to thousands of light years. If we look towards the east or west we are able to see much further. To the east we have a neighbor in the no-so-deep space, nearly a twin of the Milky Way, called The Great Andromeda Galaxy. The Andromeda Galaxy, at about 2.5 million light years, is one of the furthest objects you can see using just your eyes! And I hope to be able to help you find it, and, see for yourself another major galaxy like our Milky Way.
This article will use some techniques commonly used to navigate what at first appears as a myriad of stars up in the sky. This is the first of a periodic series you will see which will help you learn different parts of the sky and eventually you will recognize them on sight and feel a connection to the Universe. Using bright, easily-identifiable stars they will be used as pointers. Using your fingers and hand, they can be used for rough distances measured in degrees. Some of these bright stars are part of constellations you may know, but if not, now is a good time to find a few. First, if you face north using a compass if need be, you will see the Big Dipper to your left, towards the northwest, and to your right, northeast, a big capital ‘W’ of Cassiopeia, The Queen. The dipper shape is the bright section of Ursa Major, The Big Bear, and if you use the two stars at the end of the bowl section and look northward along the line they make you should see a bright star all by its self. That is Polaris, The North Star, and the fainter stars in its vicinity make a small dipper and the constellation called Ursa Minor, The Little Bear. All three of these rotate around Polaris nightly and seasonally, always above the northern horizon and are called circumpolar because of this.
So, if you use your little finger and view it outstretched to the sky it marks about one degree. Your index finger plus the next two, all three held together, viewed outstretched, they equal about five degrees, and the width of your fist about ten degrees.
To find The Andromeda Galaxy, we’ll start with the ‘W’ of Cassiopeia and an angle within the ‘W’ becomes a pointer! You may notice that pointer using the ‘W’, points to a long line with a slight curve created by three very bright stars. These three are the constellation Andromeda and are much easier to use our measuring technique to find The Andromeda Galaxy. By the way, in Greek mythology Andromeda was the daughter of Cassiopeia, but for now the middle star of the three is also a good starting point to finding The Andromeda Galaxy. Using the measure for 5-degree, your index plus the next two held together, starting from the middle star towards the ‘W’ you will see a faint star, and in that same direction from the faint star, about the same measure, you may spot a fuzzy patch of light. If so, you have viewed light that is about 2.5 million years old, the time it took when it left the galaxy – at the speed of light – to reach your eyes.
Many star clusters are visible throughout the night. If you have a planisphere or star chart, and have identified certain constellations as landmarks, if you see ‘fuzzies’ in the sky, you can use stars as pointers and your fingers and hand to gauge where on the chart you are looking and determine what object you have found! Hopefully this article was helpful to learn Ursa Major and Minor, plus Cassiopeia and Andromeda.
Steven Aggas is the Director at Apache-Sitgreaves Observatory, located in Overgaard, AZ, using the largest public viewing telescope in Arizona. Visit Apache-Sitgreaves.org for information on events and tickets. Or, consider joining the Heber Overgaard Astronomy Club/www.h-oac.org.