Spectroscopy of MASTER OT J040552.59+274716.7 in Taurus
ATel #5381; R. M. Wagner (Ohio State), C. E. Woodward (Minnesota), and S. G. Starrfield (Arizona State)
on 9 Sep 2013; 16:53 UT
Credential Certification: R. Mark Wagner (firstname.lastname@example.org)
Subjects: Optical, Cataclysmic Variable, Nova, Transient
We observed the optical transient designated MASTER OT J040552.59+274716.7 reported by Denisenko et al. (ATEL #5369) on 2013-09-06.4090 UT with the 2.4 m Hiltner telescope on Kitt Peak, Arizona. We confirm the presence of a bright transient at the position reported by Denisenko et al. Furthermore, we obtained several spectra of the transient using the OSU CCD Spectrograph (CCDS; range: 366-730 nm; resolution: 0.9 nm). The average spectrum exhibits emission lines of the Balmer series of hydrogen; He I 706.5, 667.8, 587.5 nm; He II 468.6 nm; and perhaps N III 464.0 nm. The equivalent width of H-alpha emission was 1.60 nm and with a FWHM of 1.32 nm (corrected for instrumental resolution). In addition, weaker H-beta and several of the higher order Balmer emission lines are superposed on broad (full-width of 6.2 nm at H-beta) absorption troughs. The spectrum is characteristic of a dwarf nova near maximum light. The appearance of the spectrum and outburst amplitude of at least 7.5 mag reported by Denisenko et al. suggests that the transient is a member of the WZ Sge subclass. Further time-resolved photometric observations are encouraged.