In:
Publications of the Astronomical Society of Japan, Oxford University Press (OUP), Vol. 60, No. 5 ( 2008-10-25), p. 1057-1067
Kurzfassung:
We report on results of five-epoch VLBI observations of H$_{2}$O maser emission in the M-type star IRC $-$10414, carried out with the VLBI Exploration of Radio Astrometry (VERA). The maser distribution extends over an area of 70mas$\times$260mas and exhibits a bipolar structure. The relative proper motions of 17 maser features were measured during the monitoring observations spanning nine months. The distance to IRC $-$10414 was re-estimated on the basis of the statistical treatment of parallax and the model-fitting method, yielding $D=$ 3.1$\pm$0.4kpc and $D=$ 2.0$\pm$0.2kpc, respectively. The estimated distance, $D=$ 2-3kpc, is much larger than that previously adopted. The stellar luminosity of IRC $-$10414 is also re-estimated to be $L_{\ast}\sim 9\times10^{4}$($D/$2kpc)$^{2} L_{\odot}$, much brighter by a factor of 10-20 than previously adopted ($L_{\ast} \sim 10000L_{\odot}$). The maser motions exhibit not only a spherically expanding flow with a velocity of $\sim$ 10($D/$2kpc)kms$^{-1}$, but also a faster bipolar outflow with a major axis in the north-south direction and at a small inclination angle with respect to the celestial sphere. These characteristics of the star and the circumstellar envelope seen in IRC $-$10414 are very similar to those in some supergiants exhibiting bipolar stellar mass loss.
Materialart:
Online-Ressource
ISSN:
2053-051X
,
0004-6264
DOI:
10.1093/pasj/60.5.1057
Sprache:
Englisch
Verlag:
Oxford University Press (OUP)
Publikationsdatum:
2008
ZDB Id:
2206640-8
ZDB Id:
2083084-1
SSG:
16,12
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