PTF1 J085713+331843, a new post-common-envelope binary in the orbital period gap of cataclysmic variables

Creators: van Roestel, J.; Groot, P. J.; Levitan, D.; Prince, T. A.; Bloemen, S.; Marsh, T. R.; Dhillon, V. S.; Shupe, D.; Laher, R.

Abstract

We report the discovery and analysis of PTF1 J085713+331843, a new eclipsing post-common-envelope detached white-dwarf–red-dwarf binary with a 2.5 h orbital period discovered by the Palomar Transient Factory. ULTRACAM multicolour photometry over multiple orbital periods reveals a light curve with a deep flat-bottomed primary eclipse and a strong reflection effect. Phase-resolved spectroscopy shows broad Balmer absorption lines from the DA white dwarf and phase-dependent Balmer emission lines originating on the irradiated side of the red dwarf. The temperature of the DA white dwarf is T_(WD) = 25 700 ± 400 K and the spectral type of the red dwarf is M3–M5. A combined modelling of the light curve and the radial velocity variations results in a white dwarf mass of M_(WD)=0.61^(+0.18)_(−0.17)M⊙ and radius of R_(WD)=0.0175^(+0.0012)_(−0.0011)R⊙, and a red dwarf mass and radius of M_(RD)=0.19^(+0.10)_(−0.08)M⊙ and R_(RD)=0.24^(+0.04)_(−0.04)R⊙. The system is either a detached cataclysmic variable or has emerged like from the common-envelope phase at nearly its current orbital period. In ∼70 Myr, this system will become a cataclysmic variable in the period gap.

Additional Information

© 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2017 March 10. Received 2017 February 27; in original form 2016 December 22. Published: 14 March 2017. We thank the anonymous referee for his/her helpful comments improving this manuscript, and thank T. Kupfer and C. Knigge for many useful discussions. The results presented in this paper are based on observations collected with ULTRACAM, supported by STFC grants, at the William Herschel Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Institutions de Astrofisica de Canarias. The results are based on observations of the Palomar Transient Factory. The Palomar Transient Factory is a scientific collaboration between the California Institute of Technology, Columbia University, Las Cumbres Observatory, the Lawrence Berkely National Laboratory, the National Energy Research Scientific Computing Center, the University of Oxford, and the Weizmann Institute of Science. The results are based on observations collected at the Palomar Observatory with the 200 inch Hale Telescope, operated by the California institute of Technology, its divisions Caltech Optical Observations, the Jet Propulsion Laboratory (operated for NASA) and Cornell University. Some of the data presented here were obtained by the Catalina Real-time Transient Survey (CRTS). CRTS are supported by the U.S. National Science Foundation under grants AST-0909182 and CNS-0540369. The CSS survey is funded by the National Aeronautics and Space Administration under Grant No. NNG05GF22G issued through the Science Mission Directorate Near-Earth Objects Observations Program. Funding for the Sloan Digital Sky Survey IV has been provided by the Alfred P. Sloan Foundation, the U.S. Department of Energy Office of Science, and the Participating Institutions. SDSS-IV acknowledges support and resources from the Center for High-Performance Computing at the University of Utah. The SDSS web site is www.sdss.org. SDSS-IV is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS Collaboration including the Brazilian Participation Group, the Carnegie Institution for Science, Carnegie Mellon University, the Chilean Participation Group, the French Participation Group, Harvard-Smithsonian Center for Astrophysics, Instituto de Astrofísica de Canarias, The Johns Hopkins University, Kavli Institute for the Physics and Mathematics of the Universe (IPMU)/University of Tokyo, Lawrence Berkeley National Laboratory, Leibniz Institut für Astrophysik Potsdam (AIP), Max-Planck-Institut für Astronomie (MPIA Heidelberg), Max-Planck-Institut für Astrophysik (MPA Garching), Max-Planck-Institut für Extraterrestrische Physik (MPE), National Astronomical Observatories of China, New Mexico State University, New York University, University of Notre Dame, Observatário Nacional/MCTI, The Ohio State University, Pennsylvania State University, Shanghai Astronomical Observatory, United Kingdom Participation Group, Universidad Nacional Autónoma de México, University of Arizona, University of Colorado Boulder, University of Oxford, University of Portsmouth, University of Utah, University of Virginia, University of Washington, University of Wisconsin, Vanderbilt University, and Yale University. We thank K. Verbeek for the use of the white dwarf–red dwarf model spectra that are partially made from white dwarf model spectra kindly given to us by D. Koester. JvR acknowledges support by the Netherlands Research School of Astronomy (NOVA) and Foundation for Fundamental Research on Matter (FOM). This paper was finalized during a stay by the lead authors at the Kavli Institute for Theoretical Physics, Santa Barbara, which is supported in part by the National Science Foundation under Grant No. NSF PHY-1125915.

Attached Files

Published - stx625.pdf

Submitted - 1704.01182.pdf

Files

1704.01182.pdf

Files (4.0 MB)

Name	Size	Download all
1704.01182.pdf md5:a605609b042f2b72ce08d41c1a0d60c1	1.4 MB	Preview Download
stx625.pdf md5:064ad62d1b23f6f369dc26b3d9d94e36	2.6 MB	Preview Download

Additional details

	All versions	This version
Views	0	0
Downloads	0	0
Data volume	0 Bytes	0 Bytes