A&A 431, 269-277 (2005)
DOI: 10.1051/0004-6361:20042026
Detection of the white dwarf and the secondary star in the new SU UMa dwarf nova HS 2219+1824
P. Rodríguez-Gil1, B. T. Gänsicke1, H.-J. Hagen2, T. R. Marsh1, E. T. Harlaftis3, S. Kitsionas4 and D. Engels21 Department of Physics, University of Warwick, Coventry CV4 7AL, UK
e-mail: Pablo.Rodriguez-Gil@warwick.ac.uk
2 Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
3 Institute of Space Applications and Remote Sensing, National Observatory of Athens, PO Box 20048, Athens 11810, Greece
4 Institute of Astronomy and Astrophysics, National Observatory of Athens, PO Box 20048, Athens 11810, Greece
(Received 17 September 2004 / Accepted 28 September 2004)
Abstract
We report the discovery of a new, non-eclipsing SU UMa-type dwarf nova,
HS 2219+1824
. Photometry obtained in quiescence (
)
reveals a double-humped light curve from which we derive an orbital
period of
86.2 min. Additional photometry obtained during a
superoutburst reaching
clearly shows superhumps with a
period of
89.05 min. The optical spectrum contains
double-peaked Balmer and He I emission lines from the accretion
disc as well as broad absorption troughs of
,
, and
from the white dwarf primary star. Modelling of the optical spectrum implies
a white dwarf temperature of
, a distance of
, and suggests that the
spectral type of the donor star is later than M 5. Phase-resolved
spectroscopy obtained during quiescence reveals a narrow
emission
line component which has a radial velocity amplitude and phase
consistent with an origin on the secondary star, possibly on the
irradiated hemisphere facing the white dwarf. This constitutes the first detection of line emission from the secondary star
in a quiescent
SU UMa
star.
Key words: accretion, accretion disks -- stars: binaries: close -- stars: individual: HS 2219+1824 -- stars: novae, cataclysmic variables -- stars: dwarf novae
SIMBAD Objects
© ESO 2005

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