Electronic Telegram No. 2055 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) CBAT@CFA.HARVARD.EDU (science) URL http://www.cfa.harvard.edu/iau/cbat.html NOVA ERIDANI 2009 R. J. Rudy, T. R. Prater, and R. W. Russell, The Aerospace Corporation; R. C. Puetter, University of California at San Diego; and R. B. Perry, NASA, report on 0.9- to 2.5-micron spectroscopy obtained on Nov. 26.4 UT (using the Aerospace Near-Infrared Imaging Spectrograph on the 3-m Shane reflector of Lick Observatory) of the possible nova reported on CBETs 2050 and 2053. Very strong, broad emission lines confirm this object as a nova. The width of the lines (FWHM = 4000 km/s) and the very rapid spectral development (the He I 1.083-micron line is already the strongest in the spectrum), suggest that this object may be a nova of the helium/nitrogen type. In addition to strong helium and nitrogen, the object also has a very bright O I line at 1.1287 microns. The He I 1.083-micron line shows a P-Cyg absorption extending to 3600 km/s. H. Maehara, Kwasan Observatory, Kyoto University, reports that A. Arai and M. Isogai (Kyoto Sangyo University) observed the nova with a 28-cm reflector and a low-resolution spectrograph on Nov. 26.5 UT. The nova shows a broad H_alpha emission line with a FWHM around 3200 km/s and a notable blue continuum. H_alpha and H_beta emission lines clearly show asymmetric profiles. N III (464.0 nm), N II (567.9 nm), and He I (587.6 nm) emission lines were strong. A blended line of N II (500.1 nm) and He I (501.6 nm) was also seen. These spectral features indicates that the object is a He/N nova. Maehara adds that Kazuyoshi Imamura (Okayama University of Science) obtained a low-resolution optical spectrum of the nova on Nov. 26.639 with a 28-cm telescope. The FHMW of H_alpha emission line is 3400 km/s. The spectrum can be seen at the following website URL: http://blog-imgs-32.fc2.com/t/n/b/tnblab/PN_in_Eri2009_1126639.png Maehara also forwards the following CCD magnitudes from S. Kiyota (Ibaraki, Japan), who used a 25-cm telescope of the Global-Rent-A-Scope site near Mayhill, NM, USA: Nov. 26.195 UT, V = 8.26; 26.198, B = 8.19; 26.208, R_c = 7.63; 26.208, I_c = 7.62. Visual magnitude estimates: Nov. 26.656, 8.7 (Y. Maeda, Nagasaki, Japan; forwarded by Maehara); 26.721, 8.5 (Maehara, Kyoto, Japan); 26.849, 8.4 (M. Reszelski, Szamotuly-Galowo, Poland); 26.913, 8.3 (K. Hornoch, Ondrejov, Czech Republic); 26.930, 8.0 (P. Schmeer, Bischmisheim, Germany); 26.957, 8.1 (W. Vollmann, Vienna, Austria). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2009 CBAT 2009 November 27 (CBET 2055) Daniel W. E. Green