Reference : Discovery of a New AM CVn System with the Kepler Satellite
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/109069
Discovery of a New AM CVn System with the Kepler Satellite
English
Fontaine, G. [> >]
Brassard, P. [> >]
Green, E. M. [> >]
Charpinet, S. [> >]
Dufour, P. [> >]
Hubeny, I. [> >]
Steeghs, D. [> >]
Aerts, C. [> >]
Randall, S. K. [> >]
Bergeron, P. [> >]
Guvenen, B. [> >]
O'Malley, C. J. [> >]
Van Grootel, Valérie mailto [Laboratoire d'Astrophysique de Toulouse-Tarbes > > > >]
Ostensen, R. H. [> >]
Bloemen, S. [> >]
Silvotti, R. [> >]
Howell, S. B. [> >]
Baran, A. [> >]
Kepler, S. O. [> >]
Marsh, T. R. [> >]
Montgomery, M. H. [> >]
Oreiro, R. [> >]
Provencal, J. [> >]
Telting, J. H. [> >]
Winget, D. E. [> >]
Zima, W. [> >]
Christensen-Dalsgaard, J. [> >]
Kjeldsen, H. [> >]
Jan-2011
Astrophysical Journal
University of Chicago Press
726
92
Yes (verified by ORBi)
International
0004-637X
1538-4357
Chicago
IL
[en] accretion ; accretion disks ; binaries: close ; stars: individual: SDSS J190817.07+394036.4 KIC 004547333 ; white dwarfs
[en] We report the discovery of a new AM CVn system on the basis of broadband photometry obtained with the Kepler satellite supplemented by ground-based optical spectroscopy. Initially retained on Kepler target lists as a potential compact pulsator, the blue object SDSS J190817.07+394036.4 (KIC 004547333) has turned out to be a high-state AM CVn star showing the He-dominated spectrum of its accretion disk significantly reddened by interstellar absorption. We constructed new grids of NLTE synthetic spectra for accretion disks in order to analyze our spectroscopic observations. From this analysis, we infer preliminary estimates of the rate of mass transfer, the inclination angle of the disk, and the distance to the system. The AM CVn nature of the system is also evident in the Kepler light curve, from which we extracted 11 secure periodicities. The luminosity variations are dominated by a basic periodicity of 938.507 s, likely to correspond to a superhump modulation. The light curve folded on the period of 938.507 s exhibits a pulse shape that is very similar to the superhump wavefront seen in AM CVn itself, which is a high-state system and the prototype of the class. Our Fourier analysis also suggests the likely presence of a quasi-periodic oscillation similar to those already observed in some high-state AM CVn systems. Furthermore, some very low-frequency, low-amplitude aperiodic photometric activity is likely present, which is in line with what is expected in accreting binary systems. Inspired by previous work, we further looked for and found some intriguing numerical relationships between the 11 secure detected frequencies, in the sense that we can account for all of them in terms of only three basic clocks. This is further evidence in favor of the AM CVn nature of the system.
http://hdl.handle.net/2268/109069

File(s) associated to this reference

Fulltext file(s):

FileCommentaryVersionSizeAccess
Restricted access
apj_726_2_92.pdfPublisher postprint967.77 kBRequest copy

Bookmark and Share SFX Query

All documents in ORBi are protected by a user license.