Free access
Issue
Astron. Astrophys. Suppl. Ser.
Volume 144, Number 3, June II 2000
Page(s) 379 - 389
DOI http://dx.doi.org/10.1051/aas:2000216
DOI: 10.1051/aas:2000216

Astron. Astrophys. Suppl. Ser. 144, 379-389

AS314: A dusty A-type hypergiant[*]

A.S. Miroshnichenko1,2 - E.L. Chentsov3,4 - V.G. Klochkova3

Send offprint request: A.S.Miroshnichenko,
e-mail: anatoly@physics.utoledo.edu


1 - Central Astronomical Observatory of the Russian Academy of Sciences, Saint-Petersburg, 196140, Russia
2 - Ritter Observatory, Dept. of Physics & Astronomy, University of Toledo, Toledo, OH 43606, U.S.A.
3 - Special Astrophysical Observatory of the Russian Academy of Sciences, Karachai-Cirkassian Republic,
Nizhnij Arkhyz, 357147, Russia
4 - Isaak Newton Institute of Chile, SAO Branch

Received September 1, 1999; accepted March 13, 2000

Abstract:

We present the results of our observations of the poorly-studied emission-line star AS314 which include high-resolution spectroscopy, obtained at the 6-meter telescope of the Russian Academy of Sciences, multicolor optical and near-infrared photometry. The strong H$\alpha$ line, H$\beta$ and H$\gamma$ of moderate strength and a number of weak Fe II lines were detected in emission. The Balmer lines and most of the Fe II lines show narrow PCyg-type profiles which implies a very low terminal velocity of the stellar wind. Very weak signs of emission are found in H$\delta$. Photospheric lines detected for the first time allowed us to determine the object's spectral type, A0. The luminosity, $M_{\rm bol}
\sim -8.0$ mag was estimated using several methods and implies that AS314 is a hypergiant, which is located at about 10 kpc from the Sun and has an initial mass of $\sim 20\; M_{\hbox{$\odot$ }}$. Modeling of the Balmer line profiles resulted in the following parameters of the stellar wind: $\dot{M} = 2\ 10^{-5}\;M_{\hbox{$\odot$ }}$ yr-1, $v_\infty = 75\;{\rm km\,s}^{-1}$. The star is located within the LBV strip in the HRD. Its noticeable far-IR excess is due to the circumstellar dust emission and is likely evidence of an LBV-type outburst in the past.

Key words: stars: emission-line -- stars: supergiants --circumstellar matter -- stars: mass-loss -- stars:individual - AS314

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