Properties of galactic B[e] supergiants

IV. Hen 3–298 and Hen 3–303

¹ Ritter Observatory, Dept. of Physics and Astronomy, University of Toledo, Toledo, OH 43606-3390, USA e-mail: anatoly@physics.utoledo.edu
² Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
³ Central Astronomical Observatory of the Russian Academy of Sciences at Pulkovo, 196140 Saint-Petersburg, Russia
⁴ Complejo Astronómico El Leoncito (CASLEO), Casilla de Correo 467, 5400 San Juan, Argentina
⁵ National Optical Astronomical Observatories, PO Box 26732, Tucson, AZ 85726–6732, USA
⁶ South African Astronomical Observatory, PO Box 9, Observatory 7935, South Africa

Received: 18 January 2005
Accepted: 20 February 2005

Abstract

We present the results of optical and near-IR spectroscopic and near-IR photometric observations of the emission-line stars Hen 3–298 and Hen 3–303. Strong emission in the Hα line is found in both objects. The presence of Fe ii and [O i] emission lines in the spectrum of Hen 3–298 indicates that it is a B[e] star. The double-peaked CO line profiles, found in the infrared spectrum of Hen 3–298, along with the optical line profiles suggest that the star is surrounded by a rotating circumstellar disc. Both objects also show infrared excesses, similar to those of B[e] stars. The radial velocities of the absorption and emission lines as well as a high reddening level suggest that the objects are located in the Norma spiral arm at a distance of 3–4.5 kpc. We estimated a luminosity of  5.1 and a spectral type of no earlier than B3 for Hen 3–298. Hen 3–303 seems to be a less luminous B-type object ( 4.3), located in the same spiral arm.