Wide angle view of the sky showing the location of NGC891
This was my one carefully pre-planned image for the 2014 Oregon Star Party: taking into account the large field of view afforded by the Takahashi FSQ-106, I mapped out a view that would encompass a large number of galaxies around the region of the edge-on spiral galaxy NGC891. NGC891 is a 10th magnitude galaxy approximately 10 million light years away, and was discovered by William Herschel in 1784.
The chart to the left shows where in the sky you can find this galaxy; it is in the constellation Andromeda, and at a location close to 45 degrees latitude passes almost dead overhead around 4am in late summer (this makes it a great area of the sky to image when the weather is good). The orange rectangle in the center of the chart shows the actual field of view of the image.
I compiled a list of all of the catalogued galaxies in the field of view and manually labelled all of them using Photoshop on the final image. This required dividing the image into grid areas, printing out star charts corresponding to each of the grid squares and labelling each one in turn.
The chart on the right shows what the catalogs (NGC, UGC and PGC) show as being in the field of view. To create this chart, I disabled everything except the UGC and PGC catalogs, so every object shown here is a galaxy.
Somewhat surprisingly, going through the whole image and manually labeling everything only took a couple of hours to complete, and I think this yielded a much better result than any automated labeling program would provide. In all there are 175 labelled galaxies in the image. I have a higher resolution version of this printed out on a 30″ x 20″ poster, which makes it a lot easier to read the labels.
Notably, there are many galaxies in the background that are clearly visible but have no catalog entry. I was surprised at the lack of available data on these objects; for the most part, there is no published measurement of distance based on redshift. This might be an interesting project to generate some original publishable data.
