Radio analysis reveals that Sh 2-127 consists of two distinct components - a larger weaker and more diffuse source (WB89 85A) to the northeast, consistent with ionisation by an O7 class star, and a stronger but smaller source to the southwest (WB89 85B), consistent with ionisation by an O8.5 class star. (However, it is also possible that both components are ionised by a single star.) Both components are located near the northwestern edge of a molecular cloud and are embedded in the molecular gas.
According to a 1978 study, Sh 2-120, Sh 2-121, Sh 2-127 and Sh 2-128 are all at about the same distance of 7500 parsecs and are "probably distant HII regions associated with a spiral feature more distant than the Perseus arm".
Sh 2-120, Sh 2-121, Sh 2-127 and Sh 2-128 are all at about the same distance of 7500 parsecs and are "probably distant HII regions associated with a spiral feature more distant than the Perseus arm".[
1]
Radio analysis reveals that Sh 2-127 consists of two distinct components - a larger weaker and more diffuse source (WB89 85A) to the northeast, consistent with ionisation by an O7 class star, and a stronger but smaller source to the southwest (WB89 85B), consistent with ionisation by an O8.5 class star. (However, it is also possible that both components are ionised by a single star.) Both components are located near the northwestern edge of a molecular cloud and are embedded in the molecular gas.[
2]
SIMBAD associates Sh 2-127 with the radio source KR 17, but this paper identifies KR 17 with Sh 2-187 in a completely different region of sky.[
3]
Notes
1. ^ Crampton, D., Georgelin, Y. M., & Georgelin, Y. P. (1978). "First optical
detection of W51 and observations of new H II regions and exciting stars",
Astronomy and Astrophysics, Vol. 66, 1-11. [1978A&A....66....1C]
2. ^ Rudolph, Alexander L., Brand, Jan, de Geus, Eugene J., et al. (1996). "Far
Outer Galaxy H II Regions", The Astrophysical Journal, Vol. 458, 653.
[1996ApJ...458..653R]
3. ^ Kerton, C. R. (2006). "A sharper view of the outer Galaxy at 1420 and 408
MHz from the Canadian Galactic Plane Survey - I. Revisiting the KR
catalogue and new Gigahertz Peaked Spectrum sources", Monthly Notices of
the Royal Astronomical Society, Vol. 373, 1203-1212. [2006MNRAS.373.1203K]