Spectroscopic observations of ASASSN-15bp
ATel #6992; S. C. Williams (LJMU), M. J. Darnley (LJMU), M. F. Bode (LJMU), C. M. Copperwheat (LJMU)
on 26 Jan 2015; 15:16 UT
Credential Certification: Matt Darnley (M.J.Darnley@ljmu.ac.uk)
Subjects: Optical, Cataclysmic Variable, Transient
We report spectroscopic observations of the optical transient ASASSN-15bp (ATel #6981) taken on 2015 January 25.31 UT using the FRODOSpec spectrograph (Barnsley et al. 2012) on the Liverpool Telescope (Steele et al. 2004). The spectrum shows strong, narrow (FWHM ∼300 km/s), double-peaked Hα emission. We also detect Hβ and He I (7065) emission and conclude the spectrum is consistent with the transient being a dwarf nova in outburst.
In agreement with ATel #6981, we find the position of the transient in our data to be coincident with an SDSS source, J121240.42+041655.8, which was reported as u = 20.60±0.07, g = 20.54±0.03 and i = 20.75±0.06 (Adelman-McCarthy et al. 2012). Considering the discovery magnitude of V = 11.9 (ATel #6981), this implies an outburst amplitude of over 8 magnitudes, which is unusually high for a dwarf nova.
