This is
NGC 6334, the Cat's Paw nebula. This complex of HII regions contains one larger bubble (Gum 63) adjacent to three smaller bubbles (Gum 61, Gum 62 and Gum 64b) in addition to several other partially obscured nebulae and at least eleven major infrared sources that are probably mostly cooler B stars.
It lies at the same distance as
NGC 6357, the War and Peace nebula, and is separated from it by a dark cloud. Both are near the
Sco OB4 association in the Sagittarius arm.
You can
see both nebula together in this image.
Avedisova lists 4 ionising O-stars, the hottest of which is the O5 V
HD 319699. [
1] SIMBAD associates this star with Gum 63 and gives its class as O7. Avedisova places NGC 6334 in the massive star formation region
SFR 351.30+0.70 with 176 components, including 16 masers and the well-studied infrared HII region
IRAS 17175-3544.
This nebula contains at least eleven major infrared sources that are probably mostly cooler B stars.[
2]
At the same distance as NGC 6357 and separated from it by a dark cloud.[
3]
The Gum catalog divides this nebula into six pieces (Gum 61, 62, 63, 64a, 64b and 64c).
There are many images of this spectacular nebula available online. One of the most interesting is from Dr. Travis A. Rector at the University of Alaska - Anchorage
here.
Notes
1. ^ Avedisova, V. S. & Kondratenko, G. I. (1984). "Exciting stars and the
distances of the diffuse nebulae", Nauchnye Informatsii, Vol. 56, 59.
[1984NInfo..56...59A]
2. ^ Persi, P. & Ferrari-Toniolo, M. (1982). "Near-infrared sources in the NGC
6334 molecular cloud", Astronomy and Astrophysics, Vol. 112, 292-298.
[1982A&A...112..292P]
3. ^ Neckel, T. (1984). "Polarimetric and new photometric observations in the
NGC6334/6357 region", Astronomy and Astrophysics, Vol. 137, 58-62.
[1984A&A...137...58N]