The Andromeda Galaxy and
G Class Globular Clusters
Click on the photos to see a larger image.
The Andromeda Galaxy is perhaps one the most photographed objects in the night sky. The main body of Andromeda is cataloged as Messier 31. But two other Messiers are close by — M 31 and M 110. I did not learn until I began this program that scattered across Andromeda are a number of globular clusters. Given the size of the bodies, that should come as no surprise. But I had never considered it.
This program challenges the observer to find four of these globulars, denoted G1, G76, G78, and G280. For this bit of the project, I used my first stacked astrophoto — arguably not that good. But I think it will suffice for this challenge. The first photo below has been annotated to indicate the Messiers and three G-class globular regions — G76, G78, and G280. (Unfortunately, G1 lies well outside the field of view of this photo.)
Finding the globulars on the photo was not an easy task. For starters, there is a bit of star trailing and noise in the photo that makes magnifying it a bit problematic. Fortunately, however, no trailing appeared exactly on the three globulars in question. (I can only assume that the inconsistencies of the staking process made the trailing inconsistent.) That said, however, these objects are very, very faint. It took some time and lots of “star hopping” around the photo to finally identify them. Neither Sky Safari nor the Sky X Professional was of much help, nor were my attempts to plate solve my regions of interest. There is a chart in the Program Guide that is very helpful and I found an image on the web that mapped the G-class globulars onto a photo of Andromeda. These latter two resources saved the day.
Below the first photo are three photos cropped from the main image. These crops are the regions of interest, but magnified. Beneath each photo I provide a brief account of my star hopping.
Messier 31, 32, and 110; G Class Clusters
Jack Fitzmier / October 5, 2013 / Deerlick Astronomy Village / Sharon, Georgia
2013 Peach State Star Gaze
Canon T 1i / 199 x 15 Seconds / Darks Removed / Processed in Pixinsight
G76 lies inside what appears to be an asterism that looks something like a backwards digit 7. You can see the star trailing I mentioned in the two brightest stars. At first, I wondered if one of the two fainter points of light at the “corner” of the backwards seven were also trails. That would make it a bit uncertain about which of the points was G76. However, the chart in the Program Guide clearly shows two points of light, just as in the photo, and identifies the lower of the two as G76.
After I got my bearings, G78 was relatively easy to find. I had noted on the chart in the Program Guide what appeared to be a box or rectangle pattern that had a star in the middle. It turns out that G78 is the upper right hand corner of the box, as you can see in the photo.
G 280 was really hard to identify. But the chart in the Program Guide and the photo of the G Class globulars on the web really helped. After lots of turning things around and rotating the image in Pixinsight, I finally found a pattern that I could see on the chart, the web photo, and my photo. In the magnified image above, you can make out a roughly diamond shape. The top star of the diamond is just below and to the left of the letter “in” in the word “in.” Below the diamond there is a diagonal line moving down and toward the left made up of several stars. The line runs from the lower star in the diamond to the brightest star in the field. On the chart and other web photo, I noticed that G280 was just to the right of the diagonal. It is very faint, and it took be a long time to find it.