SUMMARY OF PROPOSAL 72021
NASA/GSFC AND USRA
GREENBELT
MD USA 20771
Tel: 301-286-9447 Fax: 301-286-1684
Medium: CD ROM
Subject: CATACLYSMIC VARIABLES
ASCA OBSERVATIONS OF HYDROGEN DEFICIENT CATACLYSMIC VARIABLES
ABSTRACT
A small number of cataclysmic variables show no observable traces of hydrogen. A likely model involves a white dwarf accreting from a Roche-lobe filling, less massive, He white dwarf secondary. The peculiar evolutionary history implied by such a configuration may result in other abundance anomalies, besides the lack of hydrogen. I have analyzed the archival ASCA AO-2 data on one such system, GP Com; I have been able to derive, solely from the X-ray spectrum, overabundances of N and Ne and underabundance of Fe, as previously suggested from optical and UV spectroscopy. I propose to observe the next 3 X-ray brightest hydrogen deficient cataclysmic variables.
CO-INVESTIGATORS
| CO-I NAME | INSTITUTE | COUNTRY |
|---|
| | | |
TARGETS
| TARGET NAME | PRI | RA | DEC | TIME | TC | OFF | GIS | SIS CNT | OBS |
|---|
| 1)CR BOO | A | 207.2308 | 7.9585 | 40 ks | N | Y | P | 0.15000 | 1 |
| 3)V803 CEN | X | 200.9354 | -41.7422 | 1 ks | N | Y | P | 0.10000 | 1 |