The massive star formation region RCW 108, also called the Rim nebula, NGC 6188, and Gum 53, is ionised by the Ara OB1a
association and its core star cluster NGC 6193
. Humphreys gives a distance of 1380 parsecs for Ara OB1a.
Avedisova places it in star formation region SFR 336.43-1.26
along with the star cluster NGC 6193
, the molecular cloud [TUW2004] SFO 79
and the dark cloud DCld 336.4-01.5
Kharchenko lists the O7 V multiple star HD 150135
and 3 ionising B-stars in NGC 6193. She gives an age of 7.9 million years and a distance of 1155 parsecs. A 2008 study adds a second O-star to NGC 6193, the ultrahot O3+O6V multiple HD 150136
. The region also contains the infrared cluster RCW 108-IR
, which includes a probable O9 class star.
A good black and white hydrogen-alpha image of this region can be found here
Full colour images are here
. You can see the MSX infrared image here
HD 150135 (O6.5V; Walborn 1972) and HD 150136 (O3+O6V; Niemela & Gamen 2005) and lies at a distance of 1300 +/- 200 parsecs. The region is also embedded by an infrared cluster RCW 108-IR, which includes a probable O9 class star.[1
This vast star formation region is associated with ARA OB1A and is relatively young - most of the potential star formation in RCW 108 has yet to come.[2
The RCW catalog lists the entire nebula as RCW 108 and designates the bright core as RCW 108a.
1. ^ Wolk, Scott J., Spitzbart, Bradley D., Bourke, Tyler L., et al. (2008).
"X-Ray and IR Point Source Identification and Characteristics in the
Embedded, Massive Star-Forming Region RCW 108", The Astronomical Journal,
Vol. 135, 693-721. [2008AJ....135..693W]
2. ^ Comerón, F., Schneider, N., & Russeil, D. (2005). "Star formation in RCW
108: Triggered or spontaneous?", Astronomy and Astrophysics, Vol. 433,