SUMMARY OF PROPOSAL 82041

DR ROBIN H.D. CORBET
CORBET@LHEAMAIL.GSFC.NASA.GOV

NASA GODDARD SPACE FLIGHT CENTER/USRA
GREENBELT RD
GREENBELT
MD USA 20771
Tel: 301 286 2851 Fax: 301 286 0708
Medium: CD ROM
Subject: X-RAY BINARIES

A 1.4 DAY PERIOD IN RX J0050.7-7316


ABSTRACT

Cook et al. identified a 0.7 day period in the Be star optical counterpart of the SMC X-ray pulsar RX J0050.7-7316. Further observations by Coe & Orosz suggest that the period is twice this at 1.4 days. Either period would be extremely short for a Be/neutron star system, while the 323 s pulse period is rather long. We propose to investigate this mystery by performing ASCA observations which cover several binary periods and so study orbital flux modulation and Doppler shifts. The observations should reveal whether a eclipse occurs and determine the mass function, key parameters in understanding the the system. An extended observation will also enable the detection of other transient sources - RXTE and ASCA have shown the SMC to be extremely active in transient pulsars.

CO-INVESTIGATORS
CO-I NAME INSTITUTE COUNTRY
FRANK MARSHALLGSFCUSA
JIM LOCHNERGSFC/USRAUSA
DELPHINE PERRODINGSFC/USRAUSA
MALCOLM COESOUTHAMPTONUK

TARGETS

TARGET NAMEPRIRADECTIMETCOFFGISSIS CNTOBS
1)RX J0050.7-7316
B
 12.6862-73.2681
400 ks
N
N
P
0.01500
1