SUMMARY OF PROPOSAL 52011

DR. JEREMY J. DRAKE
JDRAKE@CFA.HARVARD.EDU

SMITHSONIAN ASTROPHYSICAL OBSERVATORY
60 GARDEN STREET
CAMBRIDGE
MA USA 02138
Tel: 617 496 7850 Fax: 617 495 7356
Medium: 4GBDAT
Subject: STARS

KSI UMA AND THE FIP EFFECT VS METAL POOR CORONAE CONUNDRUM


ABSTRACT

ASCA and EUVE spectra of active single stars, RS CVn's and Algol binaries show highly active coronae to be depleted in metals relative to the photosphere by factors of ~2-10. In contrast, spectra of lower activity stars like the Sun exhibit the "FIP Effect" in which elements with low first ionization potential (FIP), such as Fe, are enhanced relative to the photoshere - a totally opposite effect! Simultaneous ASCA and EUVE observations of the X-ray brightest intermediate activity star ksi UMa B would provide the first measure of coronal abundance anomalies at the missing key intermediate activity level, completing the picture of coronal abundance anomalies from low to high activity levels and telling us whether or not the metal poor and FIP Effect coronae are related.

CO-INVESTIGATORS
CO-I NAME INSTITUTE COUNTRY
STEPHEN DRAKENASA GSFCUSA
MARTIN LAMINGNAVAL RESEARCH LABUSA

TARGETS

TARGET NAMEPRIRADECTIMETCOFFGISSIS CNTOBS
1)KSI UMA
1
169.5521 31.5375 50 ksN
N
P
2.50000
1

TARGET 1

OBSERVATION SIMULTANEOUS WITH EUVE. CO-ORDINATION WILL BE DONE IN THE EUVE SCHEDULE: NO TIME CONSTRAINT IS PLACED ON THE ASCA OBSERVATION, OTHER THAN IT BE OBSERVED BEFORE 3 MARCH 1997