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ATEL # 1325; F. Di Mille, S.Ciroi, P. Rafanelli (UniversitÓ di Padova), H. Navasardyan (INAF-OAPD), F. Bufano (Univ. di Padova/INAF-OAPD)
on 10 Dec 2007; 20:17 UT
Password Certification: Stefano Ciroi (firstname.lastname@example.org)
Subjects: Optical, Nova
We report the spectroscopic confirmation of the optical nova candidate in M31 announced on ATEL #1311 also reported as M31N-2007-11e on CBAT M31 novae page.
Observations were carried out at Asiago Observatory using the 1.82 cm telescope + AFOSC. A 3600 sec spectrum (range 360-750 nm; 2.4 nm resolution) was obtained on 2007 Nov 29.83 about 2 days after the discovery. The spectrum shows a prominent blue continuum and Balmer lines with Halpha FWHM of about 600 km/s. In addition NaI and weak FeII emission lines with a well-marked P-Cygni profile are visible.
The object was observed again, on Dec 05.78 about 8 days post the discovery using the same instrumentation and setup. Emission lines dominate the spectrum, showing strong Balmer lines visible up to H8. FWHM of Halpha and Hbeta increased to approximately 1400 km/s. Significantly strengthened FeII lines, FeII(42), FeII(49), FeII(74), and Ca II H+K emission are now easily detectable. The NaI D is also increased in intensity and shows the most remarkable P-Cygni profile. These features suggest that M31N-2007-11e can be ascribed to the typical FeII class of the Tololo nova classification scheme (Williams 1992,AJ,104,725)