DescriptionImages

Object name: SH2

Designation(s): SH2, 156, IC1470,

Sh2-156 is also IC 1470. Galaxy Map is normally a good source for info on these but it seems confused. It gives a distance of precisely 4891 parsecs (15,300 light years) then says it is estimated to be 3500 to 4000 parsecs away (11,400 to 13000 light years). Then goes on to say it is part of the star cluster NGC 7510. Huh? The cluster is about 8 tenths of a degree northeast of the nebula and about 10,000 light years distant. Parts of Sharpless 2-157 (8000 lightyears) do extend into the field with NGC 7510 but certainly, Sh2-156 does not.

There are many other fuzz patches in the field. SIMBAD only identified the brighter ones. I've prepared an annotated image of these. Most carry very unfamiliar designations. The BF catalog is one of HII regions, GN is a reflection nebula. BDS denotes a star cluster. One small fuzz patch that is HII to the south and reflection to the north was centered on the position of an IR source found by IRAS. I don't know if the nebula is the optical counterpart to what IRAS was seeing or not. If so IRAS probably was looking at new stars buried in dust and gas that don't show visually. Some of the HII regions come through blue in my image. I'm guessing they have a reflection component as well as HII and my chip, being rather red insensitive, is seeing the reflection part better than the HII.

Due to clouds, I was only able to use half my green and blue data but all of the red was used. That should have favored the HII yet apparently didn't.

14" LX200R @ f/10, L=4x10' R=2x10'x3 GB=1x10'x3, STL=11000XM, Paramount ME