Vazquez and Baume provide a good overview of Havlen-Moffat 1
, which may be associated with this HII region. [1
It contains the infrared cluster [DBS2003] 118
at a distance of 2700 parsecs. [2
Avedisova places it in star formation region SFR 348.31-1.05
with 2 masers and the radio source CTB 38
The larger region around RCW 121, RCW 122 and RCW 123 (Sh 2-5) is spectacular in infrared. This Spitzer image shows only a part of this region.
While not as detailed, this MSX image
shows a wider view of the region in which the compact HII regions RCW 121 and 122 are seen to be bright knots at the rim of a vast star forming cavity centred on the ionising cluster Havlen-Moffat 1 and filled by the diffuse HII region RCW 123.
Curiously, a 2009 paper by Arnal, Duronea and Testori uses the 1972 distance estimate of 5000 pc despite the fact that this estimate was computed using the now discredited kinematic technique. The 2009 authors give no reason for this choice. [3
] The lower estimates of approximately 3000 pc use photometric techniques and are more likely to be accurate.
1. ^ Vázquez, R. A. & Baume, G. (2001). "The open cluster Havlen-Moffat No. 1
revisited", Astronomy and Astrophysics, Vol. 371, 908-920.
2. ^ Dutra, C. M., Bica, E., Soares, J., et al. (2003). "New infrared star
clusters in the southern Milky Way with 2MASS", Astronomy and Astrophysics,
Vol. 400, 533-539. [2003A&A...400..533D]
3. ^ Arnal, E. M., Duronea, N. U., & Testori, J. C. (2009). "The molecular
complex associated with RCW 121 and RCW 122", Revista Mexicana de
Astronomia y Astrofisica Conference Series, Vol. 35, 48-49.