Astrometry of the OH masers of 4 Mira stars
نویسندگان
چکیده
The OH main line masers in circumstellar shells were observed with astrometric VLBI in order to accurately determine the position of the star, as well as its motion, including the parallax. Results are presented on 4 Mira stars monitored for 2-8 years with the VLBA. The data show that in some stars the VLBI detection is dominated by blue-shifted emission that is associated with the stellar image amplified by the maser shell in front of the star. In other cases the maser is not directly tied to the stellar position, but still persistent enough to measure proper motion and parallax.
منابع مشابه
Improved VLBI astrometry of OH maser stars
Aims. Accurate distances to evolved stars with high mass loss rates are needed for studies of many of their fundamental properties. However, as these stars are heavily obscured and variable, optical and infrared astrometry is unable to provide enough accuracy. Methods. Astrometry using masers in the circumstellar envelopes can be used to overcome this problem. We have observed the OH masers of ...
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