SUMMARY OF SEQUENCE NUMBER 200039

SUMMARY OF SEQUENCE NUMBER 200039

Title: FK COM: SHROUDED IN MYSTERY

Observer: Buzasi

Subject Category: Normal Stars and WD

Seq: 200039 ObsId: 00614

Long-term Plan bin: no LTS bin

ABSTRACT

FK Com is a single G-type giant rotating near the breakup velocity which is considered to be a recently coalesced binary. While generally displaying extreme levels of activity, FK Com is highly variable and surprisingly underluminous at X-ray wavelengths. This observed deficiency may be due either to obscuring material around the star, or to a dynamo mechanism which differs from that operating in other cool stars. We propose to observe FK Com and two similar stars, HD 199178 and LW Hya, to address this issue and others, such as the contribution of flaring to the observed X-ray luminosity and the question of whether or not the corona is corotating. In the case of LW Hya, we propose to use ACIS-I for a quick first look, while we will use HETG for an in-depth study of FK Com and HD 199178.

TARGET SUMMARY

TARGET NAME RADEC TIME SI GRAT TYPE TC ROLL PRE PHASE MULTI PRI
FK COM/HD 117555
202.695417
24.233028
40.00000
ACIS-S
HETG
GO
no
no
no
no
yes
5

IMAGES

(NOTE: RASS images currently only available for targets LTS scheduled on or after Apr-09-2000)

Roll/Visibility

PARAMETERS

Obscat Parameters