SUMMARY OF PROPOSAL 72001
SPACE APPLICATIONS CORPORATION
9315 LARGO DRIVE WEST, SUITE 250
LARGO
MD/PRINCE GEORGES USA 20774
Tel: 301-614-5704 Fax: 301-324-9278
Medium: CD ROM
Subject: STARS
IS ZETA OPH PREPARING FOR ANOTHER MAJOR MASS EJECTION?
ABSTRACT
The rapidly rotating non-radial pulsator, Zeta Oph, an O9.5V(e) star, has a history of mass ejections and the formation of shells. Over a period of 15 years, this star has been observed by the IPC, PSPC, and SIS instruments. The combined observations suggest that the emission appears to be monotonically increasing (a factor of 3 increase in flux over this time span). During the last 5 years, the rate of change in X-ray emission increased a factor of 10 as compared to the rate between 1980 and 1990. This rate change may be due to the distortion of surface magnetic field activity, and a precursor to another mass ejection. Spectral analysis of our previous ASCA observation of this star supports this scenario. We propose two ASCA observations to continue monitoring this O star.
CO-INVESTIGATORS
| CO-I NAME | INSTITUTE | COUNTRY |
|---|
| MICHAEL CORCORAN | USRA/GSFC | USA |
| SHUNJI KITAMOTO | OSAKA UNIVERSITY | JAPAN |
TARGETS
| TARGET NAME | PRI | RA | DEC | TIME | TC | OFF | GIS | SIS CNT | OBS |
|---|
| 1)ZETA OPH | C | 249.2875 | -10.5672 | 35 ks | N | Y | P | 0.39000 | 2 |
TARGET 1
WE WOULD LIKE THESE 2 OBSERVATIONS TO BE SPACED AT LEAST 6 MONTHS APART.