Avedisova places Sh 2-50 in the star formation region
SFR 16.90-1.06 along with the star cluster Dolidze 28.
She says that the nebula is ionised by the Wolf-Rayet star MR 115. [
1] However,
MR 115 is located in a completely different location and this seems to be a typo for the Wolf-Rayet star
WR 115, which SIMBAD notes as the central star of Dolidze 28.
Interestingly, Sh 2-50 is prominent at
hydrogen-alpha and
radio frequencies but is not visible in MSX infrared images.
The radio image may in fact be showing the supernova remnant
SNR G16.8-1.1. G16.8-01.1 and the microquasar
LS 5039 lie behind Sh 2-50 at a distance of 2900 pc. [
2]
A 2011 paper looked at the relationship between SNR G16.8-1.1 and the hydrogen-alpha emission in this direction and found no clear association, providing further evidence that the supernova remnant is a distinct object. [
3]
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. ^ Ribó, M., Paredes, J. M., Romero, G. E., et al. (2002). "LS 5039: A
runaway microquasar ejected from the galactic plane", Astronomy and
Astrophysics, Vol. 384, 954-964. [2002A&A...384..954R]
3. ^ Stupar, M. & Parker, Q. A. (2011). "Catalogue of known Galactic SNRs
uncovered in Hα light", Monthly Notices of the Royal Astronomical Society,
Vol. 414, 2282-2296. [2011MNRAS.414.2282S]