Andromeda Galaxy (M31) Space Walk Among the Stars

Charts to accompany the MP3 guide.


Chart 1: Finding the general area in the sky.
Find the Big Dipper and use the "pointer stars" at the end of the "bowl" to find Polaris, the North Star. Then find the "W" of Cassiopeia. The point of the "W" on the right has a star off it that will point to Alpheratz. Then backtrack along the two chains of stars that make up the constellation Andromeda. Take the second pair of stars and find the third star up, then look offset just a little for a dim little oval cloud. Binoculars will help spot it.


M31 finder chart

Chart adapted from Cartes du Ciel.



Chart 2: Finder chart for the various objects cited in the MP3 guide. The red "+" identifies the core of M31. Stars used to find the various objects are circled in orange. The green lines denote the most easily visible sections of M31's dark dust lanes. The star cloud NGC 206, as well as double stars Struve 44 (STF 44), Struve 64 (STF 64), and Struve 79 (STF 79) are also labeled. The red letters at bottom refer to the Bonus Challenge (see below). Notice the orientation has East up and north to the right. All of the following images and charts are in the same orientation, though they vary in scale.


M31 close up finder chart

Chart adapted from Cartes du Ciel.



Image: M31, the Andromeda Galaxy. Hold cursor over the image to see objects from the MP3 space walk labeled. The three stars at top are used to find STF 79 and should be visible in a finderscope. The stars identified within the galaxy itself are used to see how far you can trace the glow of the galaxy on the northeastern side in your telescope. Once you have oriented yourself in the telescope you realize that you're only seeing the inner section of the galaxy--the section that looks yellower in the image. The bluer outer arms in images extend much farther out. Note that East is up in this image, which matches the chart above.


(Image by Adam Block and Tim Puckett)



Image: NGC 206, a huge, bright star cloud in the Andromeda Galaxy. This is a close-up showing the individual stars. In backyard telescopes, it will look like an ill-defined nebulous patch.


NGC 206

(Adam Block-NOAO-AURA-NSF)



Bonus Challenge: Finder image for globular cluster G1 (Mayall II), the brightest globular cluster in the Andromeda Galaxy. Globular clusters exist in a halo around large galaxies. G1 is one of more than 450 globular clusters known to exist in M31. This cluster is 13.7 magnitude, making it visible in a dark sky with moderate to large backyard telescopes, though experienced observers with smaller scopes may be able to pick it out under excellent conditions. The yellow letters refer to the red-lettered stars in Chart 2 above. The first image is one degree wide. The yellow rectangle shows the area covered by the detail image that follows, which is 15 arcminutes wide and equates roughly to a telescope's high power field of view. The galaxy to the lower left of star "A" is UGC 330, 14.7 magnitude. For reference, star "B" is 8.5 magnitude. Note how far away from M31 the cluster is in the sky, yet it's part of that galaxy (130,000 light years from the core). East is up, north to the right in both images to match the other charts and images.


Finder image for G1

(Digital Sky Survey image)



Globular cluster G1 (Mayall II) is the upper of three objects forming a tiny triangle in this image, the other two being stars in our own galaxy, along with all the other stars in this image. The cluster is only about 5" in apparent diameter. This image is 15 arcminutes wide. East is up and north is to the right to match the other charts and images on this page.


Globular cluster G1 (Mayall II)

(Digital Sky Survey image)



Hubble Space Telescope image of G1 (Mayall II). This view is comparable to (or even better than) what a globular cluster in our own galaxy looks like in a large backyard telescope. The cluster is approximately 1,000 light years in diameter. The two stars are the two forming the tiny triangle with G1 in the previous image.


HST image of G1

(Michael Rich, Kenneth Mighell, and James D. Neill (Columbia University), and Wendy Freedman (Carnegie Observatories) and NASA)



If you were able to find G1 and you'd like to find more globular clusters in M31, or if you just want to see some fantastic images of M31, go to Rob Gendlers' Globular Star Clusters of M31 page. Wow.



Contact: spaceman@astronomerica.awardspace.com