EDP Sciences
Free access
Volume 438, Number 3, August II 2005
Page(s) 949 - 955
Section Stellar structure and evolution
DOI http://dx.doi.org/10.1051/0004-6361:20042274

A&A 438, 949-955 (2005)
DOI: 10.1051/0004-6361:20042274

A search for very active stars in the Galaxy

First results
G. Tsarevsky1, 2, 3, José A. de Freitas Pacheco4, N. Kardashev2, P. de Laverny4, F. Thévenin4, O. B. Slee1, R. A. Stathakis5, E. Barsukova6, V. Goransky7 and B. Komberg2

1  Australia Telescope National Facility, CSIRO, PO Box 76, Epping, NSW 1710, Australia
    e-mail: gregory.tsarevsky@atnf.csiro.au
2  Astro Space Center, Lebedev Physical Institute, 84/32 Profsoyuznaya St., 117997 Moscow, Russia
3  Isaac Newton Institute of Chile, Moscow Branch, 13 Universitetskij Pr., Moscow 119992, Russia
4  Observatoire de la Côte d'Azur, BP 4229, 06304 Nice Cedex 4, France
    e-mail: thevenin@obs-nice.fr
5  Anglo-Australian Observatory, PO Box 296, Epping, NSW 1710, Australia
6  Special Astrophysical Observatory, Nizhnij Arkhyz, Karachaevo-Cherkesia 369167, Russia
7  Sternberg Astronomical Institute, 13 Universitetskij Pr., Moscow 119992, Russia

(Received 28 October 2004 / Accepted 9 February 2005 )

We report the first results of a systematic search near the plane of the Galaxy for so-called very active stars (VAS), which are characterized by a hard X-ray spectrum and activity in the radio domain. Candidates with hard X-ray binary-like spectra have been selected from the Bright ROSAT Source Catalogue in the Zone of Avoidance ( $\vert b \vert < 20^{\circ}$) and were tentatively identified in GB6/PMM/NVSS radio surveys. Most of them were observed with the ATCA and VLA. Precise radio coordinates have led to unambiguous optical identification for 60 candidates, and a sub-sample of five of them has been observed with the VLT. Also some discovery and confirmatory spectra were obtained with the AAT (4-m) and BTA (6-m). Spectroscopy with moderate dispersion, made with the FORS1 spectrograph of the VLT has revealed two stellar objects (one of them, VASC J1628-41, is definitively a binary VAS), one new AGN and two featureless spectrum sources. One of these objects, VASC J1353-66, shows marginal evidence of proper motion, which, if confirmed, would imply the discovery of a new type of galactic source.

Key words: stars: activity

SIMBAD Objects

© ESO 2005