The massive OB cluster Trumpler 27
visible towards the edge of this nebula lies at a distance of 1211 pc according to Kharchenko.[1
A 2008 paper by Piskunov, Schilbach, and Kharchenko et. al. finds that NGC 6383 has about 400 solar masses and Trumpler 27 has about 1600 solar masses.[2
] Although both clusters appear to lie at about the same distance, it is the less massive cluster that ionises the nebula, presumably because HD 159176 lies within a large cloud of molecular hydrogen but the area around Trumpler 27 is clear of such gas.
The clusters and field stars in this region (which include several Wolf-Rayet stars) are visible in this false-colour hydrogen-alpha image
from the Milky Way Explorer.
A more detailed black-and-white SuperCOSMOS hydrogen-alpha image is available here
Bica et.al. report an infrared star group, [BDS2003] 102
, within the nebula. [3
Curiously, a 2000 paper by Dutch and US astronomers, which is otherwise very thorough, claims that NGC 6383 is a member of the Sgr OB1
association. In fact Sgr OB1 is located several degrees away on the opposite side of the galactic centre. [4
1. ^ Kharchenko, N. V., Piskunov, A. E., Röser, S., et al. (2005).
"Astrophysical parameters of Galactic open clusters", Astronomy and
Astrophysics, Vol. 438, 1163-1173. [2005A&A...438.1163K]
2. ^ Piskunov, A. E., Schilbach, E., Kharchenko, N. V., et al. (2008). "Tidal
radii and masses of open clusters", Astronomy and Astrophysics, Vol. 477,
3. ^ Bica, E., Dutra, C. M., Soares, J., et al. (2003). "New infrared star
clusters in the Northern and Equatorial Milky Way with 2MASS", Astronomy
and Astrophysics, Vol. 404, 223-232. [2003A&A...404..223B]
4. ^ van den Ancker, M. E., Thé, P. S., & de Winter, D. (2000). "The central
part of the young open cluster NGC 6383", Astronomy and Astrophysics, Vol.
362, 580-584. [2000A&A...362..580V]