NGC 7137 was found on November 17, 1784, by Friedrich Wilhelm Herschel, commonly known as William Herschel, using his famous 20 foot reflector (18.7" aperture). He cataloged the object as #261in class II, Faint nebulae, as part of his April 27, 1786 paper "Catalogue of One Thousand new Nebulae and Clusters of Stars" (pp. 457-499 [ADS: 1786RSPT...76..457H]). His description read "Faint, irregularly Round, less than 1' diameter". I haven't been able to determine the observing conditions of that particular night, but maybe someone who has studied Herschel's papers in more detail can enlighten us.
NGC 7137 lies at a distance of about 25 Mpc, placing it at the western edge of the Perseus supercluster. Based on 2MASS data it is determined to be about 28 x 24 kpc in size.
NGC 7137 lies in the western most part of Pegasus, very close to the Milky Way. There are no other NGC objects in a ten degree radius around it. Only 13 log entries exist in www.deepskylog.org so I guess it is not a very popular object. Nevertheless I found it a very impressive sight in my 20" telescope!
After finally having completed the H400 list I started observing objects from the HII and Herschel 2500 lists. I observed the galaxy on October 8, 2015. My notes are
At 545x I see a large, round smudge next to a fairly bright star. Occasionally a stellar nucleus lights up in the center. I see two arms: one on the west side towards the star and one on the south side running west. The third arm to the north east remains invisible. On the south side I see a dark lane separating the arm from the nucleus and another one on the west side. Despite it being a faint object it is very spectacular!
I made this very crude drawing on my iPhone. Yes, I know there's a lot to improve but it is the thought that counts :-)
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