SUMMARY OF PROPOSAL 42060
DR. STEVEN H. PRAVDO
CALIFORNIA INSTITUTE OF TECHNOLOGY
CA USA 91109
PASADENA
M.S. 306-438, 4800 OAK GROVE DR.

  E-mail: SPRAVDO@CCMAIL.JPL.NASA.GOV	Tel: (818) 354-3131	Fax: (818) 354-8887
  Medium: 2GBDAT

Subject: X-RAY BINARIES                                              
  Title: GX301-2 SPECTRA AND PULSE PERIODS DURING THE PRE-PERIASTRON AND NEAR-APASTRON FLARES


Abstract:
 GX301-2 is an X-ray pulsar in a binary system with WRA 977. In a 1994 ASCA-BATSE
 observation Pravdo et al. discovered a periodic near-apastron flare accompanying the
 known pre-periastron flare. They suggested that a circumstellar disk around WRA 977
 can account for the periodic flares and the spin-up seen since 1984, by supplying
 matter for the flares and angular momentum for the spin-up. We will observe the
 flare spectra and look for evidence of the disk from measurements of the low-energy
 absorption and the iron line and edge energies. We will also measure phase-resolved
 spectra to search for changes between the flare and quiescent spectra. Finally we
 will make further pulse period measurements to search for mini-spin-ups correlated with the flares.

 Co-Is:
   1  LORELLA ANGELINI    	NASA/GSFC                     USA       
      ANGELINI@LHEAVX.GSFC.NASA.GOV	(301) 286-3607
   2  CHARLES DAY         	NASA/GSFC                     USA       


Target Name           PRI RA        Dec        Time TC  Off GIS SIS_Cts  Obs
-------------------   --- --------  --------   ---- --  --- --- -------  ---
GX301-2 PP FLARE       0  186.6542  -62.7697    20   Y   N   P  15.00000   1 
          
Phase Critical Oservation:
          Epoch: 43906.0600  Period:  41.50800000  Min:  0.9540   Max:  0.9780
GX301-2 NA FLARE       0  186.6542  -62.7697    30   Y   N   P  5.00000   1 
          
Phase Critical Oservation:
          Epoch: 43906.0600  Period:  41.50800000  Min:  0.4490   Max:  0.4970