Avedisova lists 4 ionising O-stars: the O7 V
HD 144918, the O7 V:
HD 330386, the O8.5 V
HD 144647 and the O9 IV subgiant
HD 144900. She places the nebula in star formation region
SFR 332.86+1.85 along the dark globule
FeSt 2-212.
The nebula appears to be surrounded by numerous small molecular clouds listed in the
[YSM99] catalog and is likely embedded in the compact OB association R105. Humphreys gives a distance estimate of 1580 parsecs for the R105 association. Kharchenko calls this association
Nor OB5 and lists the O9 V
HD 144695 and 4 ionising B-stars in addition to three of the O-stars mentioned by Avedisova. She gives an age of 12.8 million years and a distance of 1800 parsecs.
RCW 105 / Gum 51 has a spectacular bubble structure in infrared, as can be seen in
this MSX image.
You can see a visible light image
here.
Ionised by the O7 star HD 144918 at a distance of 1800 pc. [
1]
[YSM99] molecular cloud catalog. [
2]
Notes
1. ^ Thompson, M. A., Urquhart, J. S., & White, G. J. (2004). "A Compact Array
imaging survey of southern bright-rimmed clouds", Astronomy and
Astrophysics, Vol. 415, 627-642. [2004A&A...415..627T]
2. ^ Yamaguchi, Reiko, Saito, Hiro, Mizuno, Norikazu, et al. (1999). "Molecular
Clouds and Star Formation in the Southern H II Regions", Publications of
the Astronomical Society of Japan, Vol. 51, 791-818. [1999PASJ...51..791Y]