Nature of OH maser and SiO thermal emission towards carbon star: IRAS 05373-0810 (V1187 Ori)

Abstract

We present observational evidence that IRAS 05373-0810 is a genuine carbon star with an ISO SWS spectrum closely resembling that of R Scl. Modelling of the spectral energy distribution of IRAS 05373-0810 suggests that the star has luminosity of order of 8000 L_sun and loses mass at a rate of about 2-3*E^-7 M_sun yr^-1. The detected OH maser emission at 1612, 1665 and 1667 MHz and SiO thermal emission at 86.85 GHz towards IRAS 05373-0810 is not associated with this source. The available observations imply that these lines, typical for O-rich sources, come from the molecular cloud L 1641 in the Orion star forming region (OH) and, very likely, from the NGC 2149 molecular complex (SiO). Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, the Netherlands and the United Kingdom) and with participation of ISAS and NASA.