## SUMMARY OF PROPOSAL 72004

#### DR MICHAEL FRANCIS CORCORAN CORCORAN@BARNEGAT.GSFC.NASA.GOV

NASA-GSFC/USRA
CODE 660.2
GREENBELT
MD USA 20771
Tel: 301-286-5576 Fax: 301-286-1629
Medium: CD ROM
Subject: STARS

#### ABSTRACT

The extremely luminous star $\eta$ Car is perhaps the Galaxy's most enigmatic object. Periodic emission line variations reported by Damineli and collaborators provide evidence that the star is a binary. This provides a potential key for unlocking many of the star's secrets. Our RXTE data during the the last X-ray "low state" provides convincing support for the binary hypothesis. However, our simultaneous ASCA spectra yields significant, important challenges to the simple colliding wind models which have been proposed. ASCA spectra are clearly the best means of measuring the variable X-ray emission; we propose to continue to use ASCA to monitor the star as its flux brightens.

1)ETA CAR
A
161.2604-59.6803
60 ks
N
N
P
0.80000
1
2)ETA CAR
A
161.2604-59.6803
60 ks
N
N
P
0.80000
1

#### TARGET 1

WE WANT THIS OBSERVATION IN THE JAN-FEB 1999 OBSERVING WINDOW. THE EXACT START AND STOP TIME IS UNIMPORTANT.

#### TARGET 2

WE WANT THIS OBSERVATION IN THE JUN-AUG 1999 OBSERVING WINDOW. THE EXACT START AND STOP TIME IS UNIMPORTANT.