Optical Spectroscopy of the candidate nova M31N 2007-11b
ATel #1276; Arne Rau (Caltech)
on 13 Nov 2007; 21:50 UT
Credential Certification: Arne Rau (arne@astro.caltech.edu)
Referred to by ATel #: 1314
On 2007 November 13.29 UT a spectrum of the nova candidate M31N 2007-11b (ATel#1257) was obtained with the Double-Beam Spectrograph on the Palomar 200-inch telescope. The 400/6000 grism (3.5 angstrom FWHM) and 158/7500 grating (8.6 angstrom FWHM) were used with 2x1800s exposure, each.
The spectrum shows a blue continuum with strong hydrogen Balmer and He (4472,4685,4921,5015,5876,6678,7065) emission lines. We further detect NIII emission at 4637 Angstrom, which suggests this nova to be of the He/N class (Williams 1992, AJ, 104, 725). Note, that the expansion velocity of 1430+/-100 km/sec (based on Halpha), is atypically low for He/N novae. The emission line centroids are consistent with the average radial velocity of M31 of about -300 km/sec.
Overall, the spectrum strongly resembles that of M31 N2007-10b (ATel#1242).
