[vsnet-alert 15391] (fwd) GR Ori spectroscopy

[Taichi Kato]

  (fwd) GR Ori

===

ATEL #4811                                                           ATEL #4811

Title:  Spectroscopic confirmation of the dwarf nova nature of GR Orionis
Author:  Akira Arai (Nishi-Harima Astronomical Observatory, University
                of Hyogo), Daisaku Nogami(Kyoto University) on behalf of the Optical
                and Infrared Synergetic Telescopes for Education and Research (OISTER)
Queries:        arai at nhao.jp
Posted: 14 Feb 2013; 12:40 UT
Subjects:Optical, Cataclysmic Variable, Nova, Transient, Variables

We spectroscopically observed GR Ori with the 2.0-m Nayuta Telescope at
Nishi-Harima Astronomical Observatory on 2013 February 13.  This observation
was carried out with the low resolution mode (R~1,000) of the optical spectrograph
MALLS which covers the wavelength of 4,000-6,800 A.  GR Ori was discovered
as a possible nova in 1916 (Thiele 1916, Astron. Nachr., 202, 213), but
has long been suspected to be a dwarf nova (e.g. McLaughlin 1945, AJ, 51,
136; Kato et al. 2012, PASJ, 64, 63).  The second outburst of GR Ori was
found by R. Stubbings on 2013 Feb. 11.476 (UT) at 13.0 mag (vsnet-outburst
15096).  Our spectra of this star obtained around 2013 Feb. 13.53 (UT)
have a blue continuum showing H-alpha in absorption with an emission core,
H-beta in absorption (FWZI~1,800 km/s), and possibly He I 5876 in emission,
which give evidence of the dwarf nova nature of GR Ori.  Follow-up observations
are being continued by OISTER.