[vsnet-alert 17896] Spectroscopic Confirmation of Recent ASAS-SN CVs (ATEL)

[Taichi Kato]

Spectroscopic Confirmation of Recent ASAS-SN CVs (ATEL)

   It is worth noting that the unusual object ASASSN-14dx
has been confirmed to be a hydrogen-rich CV.

===

ATEL #6624                                                           ATEL #6624

Title:  Spectroscopic Confirmation of Recent ASAS-SN Transients as
                Cataclysmic Variable Stars 
Author: 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)
Queries:        rmw at as.arizona.edu
Posted: 26 Oct 2014; 04:57 UT
Subjects:Cataclysmic Variable, Transient

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.