SUMMARY OF PROPOSAL 52010
UNIVERSITY OF COLORADO
CAMPUS BOX 389 (CASA)
BOULDER
CO USA 80309-0389
Tel: 303-492-4051 Fax: 303-492-4052
Medium: 2GB8MM
Subject: STARS
THE CORONA OF THE REMARKABLE HERTZSPRUNG-GAP GIANT HR9024 (G1 III)
ABSTRACT
X-ray coronae of Hertzsprung-gap giants are among the hottest known (log T > 7.2); reminiscent of flares on the Sun, or on classical flare stars. Yet, the F0-G1 giants as a group are not noted for transient UV or X-ray outbursts. The paradox (flare-temperature gas, but lack of overt flaring behavior) bears on the nature of coronal heating at the crucial evolutionary juncture where shallow convective envelopes first emerge; the key transition between hot-star and cool-star X-ray activity. ASCA can add unique insight by directly detecting the hottest coronal gas; short-term variability of the multi-keV X-rays; and anomalous coronal abundances. HR9024 (G1 III), an intriguing transition object within the transition class, is a promising target to continue our program.
CO-INVESTIGATORS
| CO-I NAME | INSTITUTE | COUNTRY |
|---|
| ALEX BROWN | U. COLORADO (CASA) | USA |
| STEVE SKINNER | U. COLORADO (JILA) | USA |
TARGETS
| TARGET NAME | PRI | RA | DEC | TIME | TC | OFF | GIS | SIS CNT | OBS |
|---|
| 1)HD 223460 (HR 9024) | 1 | 357.4208 | 36.4253 | 60 ks | N | Y | P | 0.75000 | 1 |