SUMMARY OF PROPOSAL 42015 DR. ROBERT A. STERN LOCKHEED MARTIN PALO ALTO RESEARCH LABORATORY CA USA 94304 PALO ALTO 3251 HANOVER STREET E-mail: STERN@SAG.SPACE.LOCKHEED.COM Tel: (415) 424-3272 Fax: (415) 424-3004 Medium: 2GB8MM Subject: STARS Title: COORDINATED ASCA/EUVE/XTE OBSERVATIONS OF ALGOL Abstract: We propose a coordinated ASCA observation of the prototypical eclipsing binary Algol in conjunction with already approved EUVE and XTE observations. Observing the X-ray spectrum of Algol with ASCA, EUVE, and XTE will provide critical, near-simultaneous constraints on the distribution of the hottest temperature plasma in the Algol system: this is required to unambiguously determine the coronal Fe abundance. The ASCA coordinated observation will, in addition, provide critical tests of alternative scenarios which attempt to explain the low Fe abundance using resonance scattering or unresolved line emission. We are also very likely to observe at least one large X-ray/EUV flare during the course of the observation. Co-Is: 1 A. ANTUNES GSFC USA ANTUNES@XENO.GSFC.NASA.GOV (301) 286-2819 2 N. WHITE GSFC USA 3 S. DRAKE GSFC USA 4 K.P. SINGH GSFC USA 5 J.H.M.M. SCHMITT MPE/GARCHING GERMANY 6 F. NAGASE ISAS JAPAN Target Name PRI RA Dec Time TC Off GIS SIS_Cts Obs ------------------- --- -------- -------- ---- -- --- --- ------- --- ALGOL 0 47.0421 40.9557 40 Y N P 20.00000 4 REMARKS: MAXIMUM SIS COUNT RATE IS ESTIMATED FOR POSSIBLE FLARE Co-Ordinated Ob: Start: Jan 22, 1996 at 00 UT Stop: Jan 28, 1996 at 00 UT Monitored Oservation: Min. Int: 80.000 Max. Int: 150.000