SUMMARY OF PROPOSAL 62015
SPACE APPLICATIONS CORPORATION
1616 MCCORMICK DRIVE, ROOM 1055B
UPPER MARLBORO
MD/PRINCE GEORGES USA 20774
Tel: 301-925-0787 Fax: 301-925-0419
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 (1980-1995), the combined IPC, PSPC, and SIS observations of this star suggest that the X-ray emission appears to be monotonically increasing, displaying 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. Based on spectral analyses we argue that this rate change, probably due to the distortion of surface magnetic field activity, may be a precursor to another mass ejection. We propose two ASCA SIS observations to continue monitoring this very unusual single O star behavior.
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 | 3 | 249.2875 | -10.5672 | 35 ks | N | N | P | 0.39000 | 2 |
TARGET 1
WE WOULD LIKE THESE 2 OBSERVATIONS TO BE SPACED AT LEAST 6 MONTHS APART.