Summary: Mon. Not. R. Astron. Soc. 000, 000--000 (0000) Printed 25 November 1996 (MN L A T E X style file v1.3)
Timing the eclipse of HD185510 ?
C. Simon Jeffery 1;2 and Theodore Simon 3
1 Armagh Observatory, College Hill, Armagh BT61 9DG, Northern Ireland
2 School of Physics and Astronomy, University of St Andrews, St Andrews, FIFE KY16 9SS, Scotland
3 Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honoloulu, HI 96822, USA
Accepted . Received ; 1996 September 6.
HD185510 (=V1379 Aql) is an eclipsing doublelined RS CVn binary containing a K0
III/IV giant and a hot subluminous companion. An IUE ultraviolet light curve has been
obtained through the eclipse of the companion with an average time resolution of one
measurement every 19 minutes. This was sufficient to resolve all four times of contact
and, with data from previous work on this system, to derive a solution for the absolute
dimensions of the system.
The atmospheric parameters of both components have been investigated. From its
outofeclipse flux distribution, the K0 star has T eff = 4 500 \Sigma 300 K and appears to
be metaldeficient. However these measurements are sensitive to the fractional spot
coverage at the time photometry was obtained.
The IUE flux distribution, lowresolution Lyff profile and a noisy highresolution
UV spectrum of the hot companion have been analysed to obtain T eff = 31 500 \Sigma 1 500K,