Discovery of a bipolar and highly variable mass outflow from the symbiotic binary StHα 190^*

¹ Osservatorio Astronomico di Padova, Sede di Asiago, 36032 Asiago (VI), Italy
² Center of Studies and Activities for Space (CISAS "G. Colombo"), Uniersity of Padova, Italy
³ Center for Astronomy, Nicolaus Copernicus University, ul. Gagarina 11, 87100 Torun, Poland
⁴ Sternberg Astronomical Institute, Universitetskii pr. 13, Moscow 119899, Russia
⁵ Department of Physics, Univ. of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia
⁶ Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, 35122 Padova, Italy
⁷ Osservatorio Astrofisico di Catania, Via S. Sofia 78, 95123 Catania, Italy
⁸ Centro Galileo Galilei -CNAA, Calle Alvarez de Abreu 70, 38700 Santa Cruz de La Palma (TF), Spain

Corresponding author: U. Munari, ulisse@ulisse.pd.astro.it

Received: 26 January 2001
Accepted: 6 February 2001

Abstract

A highly and rapidly variable bipolar mass outflow from StHα 190 has been discovered, the first time in a yellow symbiotic star. Permitted emission lines are flanked by symmetrical jet features and multi-component P-Cyg profiles, with velocities up to 300 km s^-1. Given the high orbital inclination of the binary, if the jets leave the system nearly perpendicular to the orbital plane, the de-projected velocity equals or exceeds the escape velocity (1000 km s^-1). StHα 190 looks quite peculiar in many other respects: the hot component is an O-type sub-dwarf without an accretion disk or a veiling nebular continuum and the cool component is a G7 III star rotating at a spectacular 105 km s^-1, unseen by a large margin in field G giants.