These are quite faint objects from the Sharpless Catalogue. They are therefore also rarely imaged, especially Sh2-225. Sh2-225 is actually only the annotation of a rather small relatively bright structure (as seen by the annotations here), but by going deep (17.5 hours RASA data at f/2) this image clearly reveals that Sh2-225 is part of a very large ring-like structure. Actually, on a starless version (where I tweaked the histogram a bit) it is quite clear to me that there is a large ball shaped Ha-emitting structure obscured by dark nebulosity:
The tiny red oblong object at 2 o'clock from Sh2-227 is the planetary nebula G167.9+00.9, which is also rarely, if ever imaged.
Comments