SUMMARY OF PROPOSAL 42026
DR KOJI MUKAI
NASA-GSFC/USRA
MD USA 20771
GREENBELT


  E-mail: MUKAI@LHEAVX.GSFC.NASA.GOV	Tel: (301) 286-9447	Fax: (301) 286-1684
  Medium: 4GBDAT

Subject: CATACLYSMIC VARIABLES                                       
  Title: SPECTROSCOPIC AND ECLIPSE STUDIES OF THE UNIQUE X-RAY SOURCE UW CRB (MS1603.6+2600)


Abstract:
 UW CrB (MS1603.6+2600) was discovered during the Einstein Extended Medium
 Sensitivity Survey, and was optically identified with a 111 min eclipsing binary.
 Its nature remains unresolved: it is either an unusual low-mass X-ray binary (LMXB)
 or an unusual cataclysmic variable (CV). A ROSAT observation in the archive suggests
 a probable X-ray eclipse, but the low signal to noise ratio of the light curve
 prevents us from making a more definitive statement. Spectroscopy using the ROSAT
 data is also inconclusive in terms of the nature of this X-ray source. We request a
 60 ks ASCA observation with which to investigate the eclipse in detail and to
 establish the shape of the X-ray spectrum, to be compared with those of known LMXBs and CVs of various sub-types.

 Co-Is:
   1  ERIC SCHLEGEL       	NASA-GSFC/USRA                USA       
      (No Co-I contact data)
   2  ALAN SMALE          	NASA-GSFC/USRA                USA       
   3  CAROLINE STAHLE     	NASA-GSFC                     USA       


Target Name           PRI RA        Dec        Time TC  Off GIS SIS_Cts  Obs
-------------------   --- --------  --------   ---- --  --- --- -------  ---
UW CRB                 0  241.4408   25.8625    60   N   Y   P  0.04000   1