Good morning, Rallypoint, and welcome to the All Hallow's Eve edition of Astronomy Picture of the Day (APOD): "LDN 43: The Cosmic Bat Nebula." Lynd's Dark Nebula (LDN) 43 is found some 1,400 light years away in the constellation Ophiuchus. It is actually embedded in Lynd's Bright Nebula (LBN 7; the 'fog' surrounding LDN 43). We talked about 'dark' nebulae a couple of days ago...so what constitutes a 'bright' nebula?
The old red and blue photographic plates from the Palomar Observatory (California) again serve as the starting point. A 'bright' nebula can be either brighter on the blue (spectra) plate, similar brightness on the blue and red (spectra) plates, brighter on the red plate, or visible only on the red plate.
The light sources inside of LDN 43 are newly formed stars. The entire complex of gas and dust is roughly 12 light years long. Dr. Lynd published her catalog of bright nebula in 1965.