This pair of objects, an open star cluster and a very faint nebula, are located in the constellation of Perseus at a declination of +48 degrees.
The open star cluster, NGC 1245, is located at the bottom of the image. It is a magnitude 8 cluster located 10,000 light years away with about 200 stars. The cluster spans 10 arc-minutes in our apparent view, which corresponds to a diameter of 25 light years. The cluster stars in my image look a bit funky because the object is at the edge of my RASA full frame field of view. I also imaged this cluster with my Tak 130 back in 2019, shown
here.
The nebula is faint and about 40 arc-minutes wide, wider in apparent view than our full moon. The signal is predominantly HII but some OIII is also present. Jon Talbot has an excellent 46 hour Astrobin image of this object, shown
here.
There is some belief that this is a planetary nebula. If it is a PN, it is huge. Its size and faintness would likely mean than this is an ancient PN. SIMBAD does not identify this object and I could not find a distance for it. If it is the typical size of an older PN, say 5 light years in diameter, its distance would be about 400 light years away, making it one of the closest known PN to us.
My guess is that it is not a PN. The bright portion does not seem to have any circular/arc shape to it, which is unusual for a PN. In addition, the apparent size at 40 arc-minutes is more typical of a HII region than a PN. But I hope that scientists eventually determine that it is a PN. PNe seem more fun to image than isolated HII regions, plus it would add to the short list of interesting DSOs that are located close to earth.
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