Spectroscopic Confirmation of Recent ASAS-SN Transients as Cataclysmic Variable Stars

ATel #6624; A. Kaur (Clemson), A. Porter (Clemson), A. Wilber (ASU), R. M. Wagner (Ohio State/LBTO), C. E. Woodward (Minnesota), S. G. Starrfield (ASU), D. H. Hartmann (Clemson)
on 26 Oct 2014; 04:57 UT
Credential Certification: R. Mark Wagner (rmw@as.arizona.edu)

Tweet

We obtained optical spectra (range: 390-740 nm; resolution: 0.7 nm) between 2014 August 24.3 and 29.5 UT of seven new transient sources discovered during the course of the All Sky Automated Survey for SuperNovae (ASAS-SN; http://www.astronomy.ohio-state.edu/~assassin/index.shtml ) using the 2.4 m Hiltner telescope (+CCDS) of the MDM observatory on Kitt Peak. Based on their optical spectra, we have confirmed all of these sources as new cataclysmic variable stars. Specific details are as follows:

The spectrum of ASASSN-14fq exhibits weak Hα emission and the higher order Balmer lines in absorption, which are consistent with a dwarf nova around maximum light. Weaker absorption lines of He I 447.1 nm Na I D are also present.

ASASSN-14fu exhibits weak and broad higher order Balmer absorption lines superimposed on a blue continuum. Weak Hα and He II 468.6 nm emission may also be present.

The spectrum of ASASSN-14gk shows relatively strong Balmer absorption lines superposed on a blue continuum. Hα may also exhibit a weak emission core. Weaker absorption lines of He I (447.1 and 587.5 nm) and Na I D are also present.

ASASSN-14dx exhibits a blue continuum with very broad and weak Balmer absorption lines superposed with strong central double-peaked emission cores. In addition, double-peaked He I emission lines (447.1, 501.5, 517.4, and 587.5 nm) are also present. ASASSN-14dx was observed on two epochs 4 days apart and the spectra are nearly identical so no variability was evident.

The spectrum of ASASSN-fp exhibits Balmer absorption lines with the possible presence of weak emission cores. In addition, a very weak Na I D absorption feature can be seen.

ASASSN-14gb exhibits a narrow Hα emission line and higher order Balmer absorption lines with weak emission cores superposed on a blue continuum.

The spectrum of ASASSN-14gi shows a narrow Hα emission line superposed on a broad absorption line. No other Balmer or He absorption or emission lines were evident. A weak absorption line of Na I D is also present. Follow-up observations are encouraged.