SDSSJ212531.92-010745.9 - the first definite PG1159 close binary system
arXiv:astro-ph/0601512 · doi:10.1051/0004-6361:200600009
Abstract
The archival spectrum of SDSSJ212531.92-010745.9 shows not only the typical signature of a PG1159 star, but also indicates the presence of a companion. Our aim was the proof of the binary nature ofthis object and the determination of its orbital period.We performed time-series photometry of SDSSJ212531.92-010745.9. We observed the object during 10 nights, spread over one month, with the Tuebingen 80cm and the Goettingen 50cm telescopes. We fitted the observed light curve with a sine and simulated the light curve of this system with the nightfall program. Furthermore, we compared the spectrum of SDSSJ212531.92-010745.9 with NLTE models, the results of which also constrain the light curve solution. An orbital period of 6.95616(33)h with an amplitude of 0.354(3)mag is derived from our observations. A pulsation period could not be detected. For the PG1159 star we found, as preliminary results from comparison with our NLTE models, Teff about 90000K, log g about 7.60, and the abundance ratio C/He = 0.05 by number fraction. For the companion we obtained with a mean radius of 0.4 +/- 0.1 Rsol, a mass of 0.4 +/- 0.1 Msol, and a temperature of 8200K on the irradiated side, good agreement between the observed light curve and the nightfall simulation, but we do not regard those values as final.
4 pages, 4 figures to be published in A&A, accepted
References in corpus (2)
Cited by in corpus (15)
- On the Spectral Evolution of Hot White Dwarf Stars. I. A Detailed Model-Atmosphere Analysis of Hot White Dwarfs from SDSS DR12
- Post-common envelope binaries from SDSS - VII: A catalogue of white dwarf-main sequence binaries
- The Gaia DR1 Mass-Radius Relation for White Dwarfs
- A radial velocity survey for post-common-envelope Wolf-Rayet central stars of planetary nebulae: First results and discovery of the close binary nucleus of NGC 5189
- Periodic Variability of Low-Mass Stars in SDSS Stripe 82
- Analysis of cool DO-type white dwarfs from the Sloan Digital Sky Survey Data Release 10
- Unravelling the baffling mystery of the ultrahot wind phenomenon in white dwarfs
- On the formation of hot DQ white dwarfs
- Mysterious, Variable, and Extremely Hot: White Dwarfs Showing Ultra-High Excitation Lines I. Photometric Variability
- An extremely hot white dwarf with a rapidly rotating K-type subgiant companion: UCAC2 46706450
- Photometric variability of candidate white dwarf binary systems from Palomar Transient Factory archival data
- SDSS 1355+0856: A detached white dwarf + M star binary in the period gap discovered by the SWARMS survey
- A new period determination for the close PG1159 binary SDSSJ212531.92-010745.9
- A primer on the formation and evolution of hydrogen deficient Central Stars of Planetary Nebulæ and Related Objects
- Dynamic masses for the close PG1159 binary SDSSJ212531.92-010745.9