The Neutral Counterpart of an Uncatalogued Nebula and a Probable Interstellar Bubble around WR 53 in the Centaurus Region

MARTÍN, M. C.; CAPPA, C. E.; TESTORI, J. C.

REVISTA MEXICANA DE ASTRONOMíA Y ASTROFíSICA

UNAM. Instituto de Astronomía

Año: 2007 vol. 43 p. 243 - 255

0185-1101

From the inspection of optical images at l = 307° we have found an uncatalogued nebula of about 9 arcmin in radius, which we named G307.27+0.27. The analysis of the HI-21cm line emission distribution revealed an expanding HI shell that encircles the optical emission region. The shell, placed at a kinematical distance of 4+/-1 kpc, is suggested to be the HI counterpart of the optical nebula. CO observations at radio wavelengths, and far and mid IR data, allowed us to detect molecular gas and interstellar dust associated with the structures. The presence of an O6 star at a spectrophotometric distance compatible with that of the shell supports a stellar wind/HII region origin for the whole structure. We also report a probable HI interstellar bubble related to the Wolf-Rayet star WR 53. Its physical parameters are similar to the parameters of other HI bubbles around massive stars.