A radio map of Sh 2-120 shows a shell-like structure around a central source. Very little information is available in the literature apart from this map.
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 appears behind the much closer dark nebula
LDN 988, which has been informally called the Pincushion cloud.
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]
A radio map of Sh 2-120 shows a shell-like structure around a central source.[
2]
Pincushion cloud name for LDN 988. [
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. ^ Fich, Michel (1993). "A VLA survey of optically visible galactic H II
regions", The Astrophysical Journal Supplement Series, Vol. 86, 475-497.
[1993ApJS...86..475F]
3. ^ Clark, F. O. (1986). "The pincushion cloud - The bipolar flows in L988",
Astronomy and Astrophysics, Vol. 164, L19-L21. [1986A&A...164L..19C]