Sh 2-43

Sh 2-43 also known as RCW 156, is an emission nebula located in the constellation of Sagittarius. It is a faint, diffuse region of ionized hydrogen gas, potentially representing a localized concentration within a broader area of interstellar emission. It lies in a relatively empty patch of sky, bordered by several OB associations including Sgr OB1, Sgr OB7, and Sct OB3.

Charecterstics

The nebula includes a slightly brighter core region designated as RCW 156a and is associated with the star forming region SFR 13.62-0.76, which encompasses infrared sources, molecular clouds, and the radio H II region 013.839-0.763. It is also spatially aligned with the suspected supernova remnant GAL 013.1-00.5.
Nearby bright star HD 167720, a K2 III giant star is visible near the nebula, though it is not responsible for ionizing the nebula.