Distance to VY Canis Majoris with VERA
| Autor: | Makoto Matsui, Ryuichi Kamohara, Yukitoshi Kan-ya, Tomoaki Oyama, Takeshi Bushimata, Tetsuo Sasao, Chung Sik Oh, Takeshi Miyaji, Yoon Kyung Choi, Kenta Maruyama, Noriyuki Kawaguchi, Seiji Kameno, Yoshiaki Tamura, Katsunori M. Shibata, Mayumi Sato, Seisuke Kuji, Seiji Manabe, Masachika Kijima, Hideyuki Kobayashi, Kazuyoshi Yamashita, Akiharu Nakagawa, Kayoko Nakamura, Tomoya Hirota, Toshihiro Omodaka, Naoko Matsumoto, Takaaki Jike, Hiroshi Imai, Tomoharu Kurayama, Mareki Honma, Mi Kyoung Kim, Kenzaburo Iwadate, Satoshi Sakai, Katsuhisa Sato, Osamu Kameya, Takumi Nagayama, Miyuki Thushima |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Publications of the Astronomical Society of Japan. 60:1007-1012 |
| ISSN: | 2053-051X 0004-6264 |
| DOI: | 10.1093/pasj/60.5.1007 |
| Popis: | We report astrometric observations of H2O masers around the red supergiant VY Canis Majoris (VY CMa) carried out with VLBI Exploration of Radio Astrometry (VERA). Based on astrometric monitoring for 13 months, we successfully measured a trigonometric parallax of 0.88 +/- 0.08 mas, corresponding to a distance of 1.14 +0.11/-0.09 kpc. This is the most accurate distance to VY CMa and the first one based on an annual parallax measurement. The luminosity of VY CMa has been overestimated due to a previously accepted distance. With our result, we re-estimate the luminosity of VY CMa to be (3 +/- 0.5) x 10^5 L_sun using the bolometric flux integrated over optical and IR wavelengths. This improved luminosity value makes location of VY CMa on the Hertzsprung-Russel (HR) diagram much closer to the theoretically allowable zone (i.e. the left side of the Hayashi track) than previous ones, though uncertainty in the effective temperature of the stellar surface still does not permit us to make a final conclusion. Comment: 7 pages, 4 figures, accepted for publication in PASJ, VERA special issue |
| Databáze: | OpenAIRE |
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