ROSAT-detection of a giant X-ray flare on LkH-alpha 92.
Abstract
We report the detection of a giant X-ray flare on the classical T Tauri star LkH-alpha 92 with the ROSAT Position Sensitive Proportional Counter (PSPC). In this flare the PSPC count rate rose by a factor of more than 100 in a time interval of about 2000 sec. Our X-ray observations cover most of the rise phase as well as part of the decay phase of the flare. We model the X-ray spectra obtained at different flare phases to determine temperature and emission measure of the flaring plasma. Combining the thus derived X-ray luminosity with the observed decay time scale of approximately = 7800 sec, we estimate the total energy release of the flare in the ROSAT PSPC band (0.1 - 2.4 keV) to be approximately = 4 x 1036 erg, which is more than a factor of 104 greater than the energy release in the strongest solar flares and still more than a factor of 100 greater than that in typical fares on T Tauri stars.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- November 1993
- Bibcode:
- 1993A&A...279L..33P
- Keywords:
-
- Space Plasmas;
- Spaceborne Astronomy;
- Stellar Flares;
- Stellar Models;
- Stellar Spectra;
- T Tauri Stars;
- X Ray Astronomy;
- X Ray Spectra;
- Astronomical Spectroscopy;
- Light Curve;
- Mathematical Models;
- Proportional Counters;
- Rosat Mission;
- Stellar Luminosity;
- Astronomy