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Session 103 - Cool Stars.
Display session, Thursday, January 18
North Banquet Hall, Convention Center

[103.20] EUVE Right Angle Program Observations of Late-Type Stars

D. J. Christian, M. Mathioudakis, J. J. Drake (CEA/UCB)

The EUVE\/ Right Angle Program (RAP) obtains photometric data in four bands centered at \sim100 Å\ (Lexan/B), \sim200 Å\ (Al/Ti/C), \sim400 Å\ (Ti/Sb/Al), and \sim550 Å\ (Sn/SiO). RAP observations are up to 20 times more sensitive than the all-sky survey. We present RAP observations of the late-type stars: BD+03 301, BD+05 300, HR 1262, BD+23 635, BD+22 669, Melotte 25 VA 334, Melotte 25 1366, Melotte 25 59, Melotte 25 65, \theta^1 Tau, V834 Tau, GJ 2037, BD-21 1074, GJ 205, RE J0532-030, GJ 9287A, HT Vir, BD+46 1944, Proxima Cen, \alpha Cen A/B, HR 6094, CPD-48 10901, and HR 8883. We derive fluxes and emission measures from Lexan/B and Al/Ti/C count rates. The time variability of the sources has been examined. Most of the sources show no significant variability at the 99% confidence level. Flares were detected from the K3V star V834 Tau (HD 29697) and the K0 star BD+22 669. The BD+22 669 count rate at the peak of the flare is a factor of 10 higher than the quiescent count rate with a peak Lexan/B luminosity of 7.9 \times 10^29 erg s^-1. The V834 Tau flare was detected in both Lexan/B and Al/Ti/C bands. The peak luminosity of the flare is 1.6 \times 10^29 erg s^-1 and 8 \times 10^28 ergs s^-1 for Lexan/B and Al/Ti/C, respectively. This is a factor of 4.3 higher than the quiescent luminosity in Lexan/B, and a factor of 4.6 in Al/Ti/C\@. This work is supported by NASA contract NAS5-29298.

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