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HET Spectra of Three Recent Extragalactic Novae

ATel #923; A. W. Shafter (SDSU), E. A. Coelho (SDSU), K. A. Misselt (U. Arizona), M. F. Bode (Liverpool JMU), M. J. Darnley (Liverpool JMU), R. Quimby (U. Texas)
on 26 Oct 2006; 21:40 UT
Credential Certification: Allen W. Shafter (aws@nova.sdsu.edu)

Subjects: Optical, Cataclysmic Variable, Nova, Transient

We report optical spectroscopic observations (4280Å - 7280Å) obtained with the HET of three extragalactic novae: Nova M31 2006 No. 9 (ATEL #887), Nova M32 2006 No. 1 (CBET #591), and Nova M33 2006 No. 1 (CBET #655). The spectra were obtained on 24 Sep 2006 UT, 30 Sep 2006 UT, and 02 Oct 2006 UT, corresponding to approximately 6, 65, and 4 days post discovery, for the three novae respectively. The spectra of Nova M31 2006 No. 9 and Nova M33 2006 No. 1 revealed prominent Balmer (FWHM ~ 1600 km/s) and Fe II emission lines typical of the "Fe II" class in the nova classification system of Williams (1992). A spectrum of Nova M32 2006 No. 1 was obtained shortly after eruption by Leonard et al. (CBET #593) who reported strong Balmer and Fe II emission. Our HET spectrum of Nova M32 2006 No. 1, which was obtained much longer after eruption, continued to show strong H&alpha (EW=660Å), along with weaker H&beta, Fe II, and [N II] &lambda 5755Å emission features. These observations confirm that Nova M32 2006 No. 1 is also a member of the "Fe II" class, and establishes that it had entered the nebular phase by the time of our observations.

In addition to observations of these three novae, we also attempted to obtain a spectrum of Nova M31 2006 No. 7 (CBET #615) on 23 Sep 2006 UT, approximately three weeks after discovery. By the time of our observations, the nova had become invisible. An 1800s integration at the reported position reveled no trace of the nova. It is likely that this transient was an unusually fast nova, possibly of the "He/N" type in the Williams (1992) classification scheme.