SUMMARY OF SEQUENCE NUMBER 300012
SUMMARY OF SEQUENCE NUMBER 300012
Title: THE NATURE OF THE SUPERSOFT X-RAY SOURCE RXJ0439.8-6809
Observer: Gaensicke
Subject Category: WD Binaries and CVs
Seq: 300012 ObsId: 00643
Long-term Plan bin: 26-Jan-2000
ABSTRACT
The supersoft X-ray source RXJ0439.8-6809 is either the hottest known pre-white dwarf or an accreting double-degenerate white-dwarf binary. In the first case, RXJ0439.8-6809 puts strong constraints on the evolution of post-AGB stars; in the second case, it may have the shortest orbital period among all known accreting binaries. We propose to obtain a 40 ksec HRC-S+LETG observation, which will accurately determine the nature of the X-ray spectrum and the corresponding physical parameters, provide an accurate Rayleigh-Jeans extrapolation necessary to interprete the scheduled HST observations, possibly prove the white-dwarf nature of the X-ray source by detecting NeVIII absorption edges, and at best detect the predicted orbital period of a few minutes.
TARGET SUMMARY
| TARGET NAME |
RA | DEC |
TIME |
SI |
GRAT |
TYPE |
TC |
ROLL |
PRE |
PHASE |
MULTI |
PRI |
| RX J0439.8-6809 |
69.956667 | -68.150278 |
40.00000 |
HRC-S |
LETG |
GO |
no |
yes |
no |
no |
no |
5 |
IMAGES
(NOTE: RASS images currently only available for targets LTS scheduled on or after Apr-09-2000)
PARAMETERS
Obscat Parameters
