Discovery of H2O maser emission from the red supergiant IRAS04553-6825 in the Large Magellanic Cloud

Jacco Th. van Loon, Peter te Lintel Hekkert, Valentin Bujarrabal, Albert A. Zijlstra, Lars-Ake Nyman

Published 1998-06-15Version 1

We report the detection of 22 GHz H2O maser emission from the red supergiant IRAS04553-6825 in the Large Magellanic Cloud. It is the first known source of circumstellar H2O maser emission outside the Milky Way. The measured flux density is comparable to that expected from scaling the galactic red supergiant NML Cyg. The peak velocity agrees with the SiO maser peak velocity. A near-infrared spectrum indicates that IRAS04553-6825 has a typical LMC metallicity. We argue that, possibly as a result of the low metallicity, the H2O emission probably occurs near or within the dust formation radius, rather than further out as appears to be the case in NML Cyg and galactic OH/IR stars.