Spectroscopic and photometric observations of the M31 nova candidate, PTF11rdv
ATel #3825; A. W. Shafter, M. F. Bode, M. J. Darnley (Liverpool JMU, UK), R. Ciardullo (PSU), Y. Cao (Caltech), K. Hornoch (Astronomical Institute, Ondrejov, Czech Republic)
on 24 Dec 2011; 22:32 UT
Credential Certification: Allen W. Shafter (aws@nova.sdsu.edu)
Subjects: Optical, Nova, Transient
We report spectroscopic and photometric observations of the recent M31 nova candidate, PTF11rdv (M31N 2011-12a?), discovered by the Palomar Transient Factory (Cao & Kasliwal, ATel #3800). At our request, a spectrum (410–900 nm) was obtained by M. Shetrone on 2011 Dec. 21.18 UT with the 9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph). The spectrum reveals strong Balmer, He I (λ 587.6 nm; λ 667.8 nm; λ 706.5 nm) and O I (λ 844.6 nm) emission lines (FWHM Hα ~1500 km/s; EW Hα ~ -100.0 nm), along with weak emission features of Fe II (multiplets 37, 38, 42, 48, 49), superimposed on a flat continuum. These observations confirm that PTF11rdv is a nova in M31. We tentatively classify the nova as a member of the Fe II spectroscopic class, although the presence of strong He I emission is somewhat unusual for this class of nova at this stage of its development. Consistent with the Fe II type, the nova appears to be evolving quite slowly. Below we tabulate photometric observations of PTF11rdv obtained using the 0.65-m telescope at Ondrejov:
UT Date R Mag
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Dec. 09.915 17.26 +/- 0.09
Dec. 10.691 17.83 +/- 0.1
Dec. 11.679 18.55 +/- 0.1
Dec. 12.975 18.73 +/- 0.15
Dec. 14.887 18.76 +/- 0.15
Dec. 15.838 18.54 +/- 0.15
Dec. 18.869 18.63 +/- 0.15
Dec. 19.711 18.8 +/- 0.2
A.W.S. thanks the NSF for support through AST-1009566. K.H. thanks P. Zasche, P. Kusnirak, and J. Vrastil for assistance with the photometric observations.
