This giant star formation region at the boundary of the Vela OB1
association is a blister compact HII region lying just inside the edge of a giant molecular cloud. It is ionised by an enormous star cluster, [BDB2003] G267.92-01.06
, that is less than 1 million years old and contains about 2000 stars (about 31 of these candidate O or B class stars). The hottest of these is the O5.5V class [FP74] RCW 38 IRS 2
The RCW 38 cluster is less than 1 million years old and contains about 2000 stars (about 31 of these candidate O or B class stars). The hottest of these is the O5 class [FP74] RCW 38 IRS 2. RCW 38 itself appears to be a blister compact HII region lying just inside the edge of a giant molecular cloud.[1
Includes an embedded cluster with 200 members detectable in X-rays.[2
Avedisova adds three more ionising stars: the O4 III giant CPD -47 2963
, the O9.5 Ia supergiant HD 78344
and the B0.5 II-Ib CD -47 4551. (SIMBAD gives a cooler O6 class for CPD -47 2963 and says that it is the same star as CD -47 4551.) She places RCW 38 in star formation region SFR 267.93-1.00
with 58 components, including 2 water masers, the supernova remnant CTB 31
, at least half a dozen reflection nebulae, the HII region Gum 22
, and the star cluster Muzzio 1
A full colour infrared image was released by the ESO in 2010
. A good black and white hydrogen-alpha image of this region can be found here
, a Chandra X-ray image of the central cluster here
and a MSX 8μm infrared image here
The RCW catalog identifies four subnebulae, RCW 38a - 38d, as can be seen in this hydrogen-alpha image
Gum describes this as a "Group of small fragments - possibly one object broken up by foreground obscuration." and places it within the boundary of the much larger nebula Gum 22.
1. ^ Wolk, Scott J., Spitzbart, Bradley D., Bourke, Tyler L., et al. (2006).
"X-Ray and Infrared Point Source Identification and Characteristics in the
Embedded, Massive Star-Forming Region RCW 38", The Astronomical Journal,
Vol. 132, 1100-1125. [2006AJ....132.1100W]
2. ^ Wolk, S., Spitzbart, B., Bourke, T., et al. (2003). "The Stellar
Population of RCW 38", Bulletin of the American Astronomical Society, Vol.
35, 1219. [2003AAS...203.1005W]