Astron. Astrophys. 351, 573-581 (1999)

Spectroscopy and photometry of the pre-cataclysmic binary PG1026+002 ^*

Albert Bruch ¹ and Marcos P. Diaz <sup>2

1</sup> Laboratório Nacional de Astrofísica, CP 21, 37500-000 Itajubá - MG, Brazil
² Instituto Astronômico e Geofísico, Universidade de São Paulo, CP 3386, 01060-970 São Paulo - SP, Brazil

Received 6 May 1999 / Accepted 13 September 1999

Abstract

Time resolved spectroscopic and photometric observations of the pre-cataclysmic binary PG1026+002 are presented. An improved orbital period is derived from radial velocity measurements of the H emission component. The phasing of the variations of the equivalent width of this line confirms the suspicion expressed by Saffer et al. (1993) that the emission is intrinsic to the red dwarf and not due to a reflection effect as observed in several other pre-cataclysmic binaries. The very slight variations in the light curve detected in our photometric observations can, however, excellently be modeled as being caused by illumination of the secondary by the primary white dwarf.

Key words: stars: variables: general stars: individual: PG1026+002

* Based on observations obtained at the LNA/CNPq, Itajubá, Brazil

Send offprint requests to: Albert Bruch (albert@marina.lna.br)

© European Southern Observatory (ESO) 1999

Online publication: November 3, 1999

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