Spectroscopic classification of 2MASS_J16211735+4412541
ATel #9122; S. Scaringi (MPE), E. Mason (INAF-OA Trieste), H. van Winckel (KU Leuven), A. Escorza (KU Leuven & ULB)
on 6 Jun 2016; 21:06 UT
Credential Certification: Tom Maccarone (thomas.maccarone@ttu.edu)
Subjects: Optical, Cataclysmic Variable, Transient
We obtained a spectrum of the candidate short period binary
2MASS_J16211735+4412541 (CSS160603:162117+441254) with the high
resolution HERMES spectrograph mounted on the 1.2m Mercator telescope on
La Palma.
This system was previously identified as a contact eclipsing binary
(WUMa) by Palaversa et al. (2013, AJ, 146, 101), Lohr et al. (2013, A&A
549, 86) and Drake et al. (2014a, ApJS, 213, 9) with a period of
P=0.207852(1) days.
After the report of the recent outburst from this system (ATel #9112),
we obtained 2 x 30 minute exposure spectra on 2016-06-05.00 UT to
determine whether this outburst is associated to a possible MS+MS
merging event or a dwarf nova-type outburst from an accreting compact
object.
The spectrum shows clear H-alpha;, H-beta; and HeII 4686 Ang;
emission, with the FWHM of the H-alpha; line estimated to be ~1500 km/s.
This spectrum confirms that the 2MASS_J16211735+4412541 outburst is
associated to an accreting compact binary rather than a MS+MS merger, as
also suggested by the GALEX magnitudes (ATel #9112). In particular, it
is possible that 2MASS_J16211735+4412541 is a CV above the period gap
undergoing a dwarf nova outburst.
