The neutral counterpart of an uncatalogued nebula and a probable interstellar bubble around WR 53 in the Centaurus region

M. C. Martín, C. E. Cappa and J. C. Testori.

Serie: Trabajos publicados del IAR ; no. 786

Resumen: From the inspection of optical images at l = 307° we have found an uncatalogued nebula of about 9' 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 4ñ1 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 WR53. Its physical parameters are similar to the parameters of other HI bubbles around massive stars.