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

MONITORING X-RAY EMISSION FROM $\ETA$ CAR


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.

CO-INVESTIGATORS
CO-I NAME INSTITUTE COUNTRY
JEAN SWANKGSFCUSA
ROB PETREGSFCUSA
STEVE DRAKEGSFCUSA
AUGUSTO DAMINELIJILAUSA
KAZUNORI ISHIBASHIUMINNUSA
KRIS DAVIDSONUMINNUSA
KATSUJI KOYAMAKYOTOJAPAN
YOHKO TSUBOIKYOTOJAPAN
ROBERTO VIOTTIIASITALY
STEPHEN WHITEUMDUSA

TARGETS

TARGET NAMEPRIRADECTIMETCOFFGISSIS CNTOBS
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.