Spectroscopy of M31N 1995-11e: Not a Nova, but a Luminous Mira Variable in M31
ATel #1834; A. W. Shafter (SDSU), R. Ciardullo (PSU), M. F. Bode, M. J. Darnley (Liverpool JMU, UK), K. A. Misselt (U. Arizona), K. Nishiyama, F. Kabashima (Miyaki-Argenteus Obs.)
on 7 Nov 2008; 20:38 UT
Credential Certification: Allen W. Shafter (aws@nova.sdsu.edu)
Subjects: Optical, Nova, Transient
Referred to by ATel #: 1851
Recent photometric monitoring of M31 by
two of us (K. Nishiyama and F. Kabashima) has revealed that
the M31 nova candidate M31N 1995-11e (Nova 1995-08 in
Shafter & Irby 2001, ApJ, 563, 749)
has re-brightened over the past several months.
The object was detected again
on 2008 July 6.8 UT at m ~ 18.6 (unfiltered), and
has remained detectable up to the
present, reaching a peak brightness of m ~ 18 on
2008 September 9 UT.
We obtained a spectrum of the object on 2008 November 3 UT with the
Marcario Low-Resolution Spectrograph of the 9.2-m Hobby Eberly
Telescope. This spectrum reveals that the object is not a nova:
it has strong TiO absorption bands and narrow H&alpha emission
(FWHM ~ 350 km/s; EW ~ -7Ã
RV ~ -40 km/s) superimposed on a very red
continuum.
This suggests that M31N 1995-11e is a long-period (and very luminous)
Mira variable in M31, similar to V14148 D31C (Darnley et al. 2004, MNRAS, 353, 571;
Stanek et al. 1999, AJ, 117, 2810). The radial velocity of the H&alpha
feature, which is about 260 km/s greater than the mean systemic velocity
of M31, is consistent with that expected for a disk object in
the North-East (receding) quadrant of the galaxy, ~45' from the nucleus
along M31's major axis.