vdB 123/GN 18.27.9 is a very blue reflection nebula in Serpens Caudia
about 836 light-years distant. This is based on The Sky's distance for
the illuminating star HD 170634 of 52,888,500AU. To the west is an
orange nebula. Not H alpha pink. It is also a reflection nebula. The
only identification of the nebula I could find in SIMBAD was Name
Ser(pens) (Reflection) Nebula/Name Ser (mol) Cloud Core and GN 18.27.4,
each with a slightly different position all inside the nebula. So why
is it so orange? I couldn't find an answer. It could be seen through a
lot of dust that reddens it to this color or possibly the star in front
that is illuminating it really is red and not dust reddened so the
nebula is taking on its color. But it seems too faint though the
illuminating star of McNeil's nebula is very dim from our vantage point
due to dust. I have no answer here. If anyone has an idea let us know.

The colors of the field seem odd. Most stars are greatly reddened by
dust yet there's a large blue haze over much of the field from the
large, but dim, extent of the vdB 123 lying in front of the reddening
dust it would seem. In places all stars are blocked. SIMBAD lists a
ton of young stellar objects and HH objects in the area, most apparently
dust shrouded as I see nothing of most of them in my image. Those I do
see are labeled in the annotated image. Y*O for Young Stellar Objects
and HH for the one Herbig Haro object I could identify. Note nearly all
the stars and Y*Os have the same color. The YSOs were mostly K and M
stars so are rightly red but there should be some variation but there
isn't. I think this a good sign the color is mostly from dust reddening.

There were a very few YSOs that were A stars so should have been rather
blue but even they were redder than an A star should be, another
indication of dust reddening. When I adjusted those to be about right
the blue of the reflection nebula went way too blue indicating it is
likely in front of much of the dust. The annotated image notes the
spectral type of a few of these young stellar objects

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Rick
--
Prefix is correct. Domain is arvig dot net

Attached Thumbnails