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Session 60 - Multiple Stars.
Display session, Wednesday, June 12
Great Hall,

[60.12] Coordinated EUVE/ASCA/XTE/VLA Observations of Algol

R. A. Stern, J. R. Lemen (LSAL), S. Antunes (Hughes/STX), S. A. Drake (NASA/USRA), F. Nagase (ISAS), J. H. M. M. Schmitt (MPE), K. P. Singh (Tata Inst.), N. E. White (NASA/GSFC)

EUVE, ASCA, and XTE observed the eclipsing binary Algol (\beta Per) from 1--7 Feb 96. EUVE was continuously pointing at Algol (with the exception of earth block, SAA passages, etc.) for \sim 2 binary orbits, with a net exposure time of 160 ksec, ASCA for \approx 40 ksec net exposure in 4 separate pointings, and XTE for \approx 90 ksec in 45 pointings. The objective of the combined EUV/X-ray observations is to definitively determine the temperature distribution and Fe abundance in the quiescent spectrum, and, with luck, catch a flare or two. In addition, \approx 24 hours of coordinated VLA time were scheduled, with the primary goal of comparing the microwave data with the XTE spectrum to search for evidence of hard X-ray emission characteristic of microflares. The EUVE quicklook lightcurve data in the 70-170 Å\ band show evidence of continual variability, most likely from a combination of geometric effects (i.e. eclipses and rotational modulation) and flaring. One moderate (\approx \times2) flare is evident in the EUVE data: the flare decay should be visible in the (as yet unreduced) XTE data. The ASCA data were taken largely during quiescent periods, which will be helpful in a combined emission measure and Fe abundance analysis. We will discuss preliminary results from this coordinated campaign, including first attempts at modeling the combined spectra.

Program listing for Wednesday