Optical Spectroscopy of the M31 nova M31N-2009-10b

ATel #2248; F. Di Mille (LCO/AAO), S. Ciroi (Padova University),  H. Navasardyan,(INAF/OAPD), Sebastien Lepine (American Museum of Natural History), Liese von Zee, Kate L. Barnes (Indiana University), Dieter H. Hartmann, Sean D. Brittain, Adria C. Updike, Aman Kaur (Clemson University), G. G. Williams(MMTO), W. Pietsch(MPE), A. Siviero, T. Saguner(INAF/OAPD), M. Orio(INAF/OAPD, Univ. of Wisconsin), P. Rafanelli, A. Bianchini(Padova University)
on 20 Oct 2009; 06:32 UT
Credential Certification: Stefano Ciroi (stefano.ciroi@unipd.it)

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The bright extragalactic nova M31N-2009-10b was observed at Asiago Observatory (Italy ) on 2009 Oct 15 and 17 and at KPNO (Kitt Peak National Observatory) near Tucson, AZ, on 2009 Oct 17 and 19. The first spectrum (3x1200 sec exposures,range 355.0-766.0 nm,resolution 1.5 nm ) was obtained at Asiago with the 1.82 telescope + AFOSC on October 15.02 UT, approximately 2 days after the discovery (see CBET #1967). It shows a prominent blue continuum with absorption lines of the Balmer series flanked by a weak emission(see also CBET #1980). In the second AFOSC spectrum (2400 sec. exposure,range 355.0-766.0 nm, resolution 2.3 nm) obtained on Oct. 17.88 UT the blue continuum became redder while the flux of the emission lines increased. The object was observed on the same night also with the Asiago 1.22 m telescope +Boller & Chivens spectrograph in the spectral range 543.2-667.0 nm and with a spectral resolution of 0.15 nm. A clear P-Cygni profile at H-alpha shows a FWHM of 1100 km/s and a velocity of the absorption component of about -1400 km/s.
Spectroscopic observations were carried out with HYDRA on the WIYN 3.5m telescope¹ at KPNO using the 600@10.1 l/mm grating and the blue fiber bundle (3" fibers). A 300 sec exposure was obtained on 2009 Oct 17 with wavelength coverage of 410-690 nm; 0.45 nm resolution. The spectrum shows a strong blue continuum and prominent Balmer lines with P-Cygni profiles and Fe absorption lines. The Balmer lines indicate blue-shifted absorption to -2500 km/s and red-shifted emission to at least +1600 km/s, with a FWHM (emission-line) of about 1120 km/s. The nova was observed again with HYDRA on the WIYN 3.5m telescope on 2009 Oct 19 with the same instrumentation and setup described above. Three 300 sec exposures were obtained. The spectrum shows a strong red continuum and prominent Balmer lines in emission. The Balmer lines exhibit weak P-Cygni profiles with blue-shifted emission to -1800 km/s and red-shifted emission to at least 3200 km/s. The FWHM of Halpha is now approximately 1630 km/s. An optical-red spectrum was obtained at the KPNO Mayall 4-meter telescope, on the night of 2009 October 17 (UT) with the RC spectrograph in conjunction with the LB1A thick CCD detector. The nova was imaged through a 1.5 arcsecond slit, and the light was dispersed on the BL-181 grating (316 lines/mm) in first order. This configuration yields spectral coverage of 5740A-8850A with a resolution of 1.74A per pixel. Six exposures of 150 seconds each were obtained. The spectrum was calibrated using a HeNeAr arc lamp and exposures of the spectro-photometric standard PG 0216+032. Based on these spectroscopic data we find that M31N-2009-10b resembles the slowly rising, luminous FeII nova M31N-2007-11d, as described in A. W. Shafter, et al. 2009, ApJ 690, 1148. We are also monitoring the nova photometrically with the SARA 0.9m and the robotic S-LOTIS 0.6m telescope, both located at KPNO.

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The, WIYN Observatory is a joint facility of the University of Wisconsin, Indiana University, Yale University, and the National Optical Astronomy Observatory.