Electronic Telegram No. 2391 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION CBAT Director: Daniel W. E. Green; Room 209; Dept. of Earth and Planetary Sciences; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbat@iau.org; cbatiau@eps.harvard.edu URL http://www.cfa.harvard.edu/iau/cbat.html NOVAE IN M31 Kamil Hornoch, Astronomical Institute, Ondrejov; and Jesus M. Corral- Santana and Jorge Casares, Instituto de Astrofisica de Canarias and Universidad de La Laguna, report Sloan r' and narrow-band H_alpha photometry of recently discovered transients in M31 designated M31N 2010-06a, M31N 2010-06b, M31N 2010-06c, M31N 2010-06d, and M31N 2010-07a. Sloan r' and narrow-band H_alpha CCD frames were taken by Corral-Santana with the 2.54-m Isaac Newton Telescope (+ WFC) at La Palma on July 10.200, 10.210, and 11.210 UT. When comparing measurements in Sloan r' and H_alpha, they notice strong excess in H_alpha emission, suggesting that these objects are novae. The only exception is M31N 2010-07a, but the measurements for this object are fully consistent with a young nova having still weak H_alpha emission. Sloan r' and [H_alpha] magnitudes measured by Hornoch for M31N 2010-06a (cf. CBET 2341): July 10.200 UT, r' = 17.86 +/- 0.05; 10.210, [H_alpha] = 16.25 +/- 0.07; 11.210, r' = 18.05 +/- 0.05. Magnitudes for M31N 2010-06b (cf. CBET 2342): July 10.200, r' = 19.48 +/- 0.08; 10.210, [H_alpha] = 17.7 +/- 0.1; 11.210, r' = 19.54 +/- 0.06. Magnitudes for M31N 2010-06c (cf. CBET 2343): July 10.200, r' = 18.89 +/- 0.06; 10.210, [H_alpha] = 16.63 +/- 0.07; 11.210, r' = 18.95 +/- 0.04. Magnitudes for M31N 2010-06d (cf. CBET 2347): July 10.200, r' = 19.31 +/- 0.07; 10.210, [H_alpha] = 18.1 +/- 0.1; 11.210, r' = 19.24 +/- 0.06. Magnitudes for M31N 2010-07a (cf. CBET 2358): July 10.200, r' = 17.31 +/- 0.05; 10.210, [H_alpha] = 17.34 +/- 0.08; 11.210, r' = 17.91 +/- 0.04. Kamil Hornoch, Astronomical Institute, Ondrejov; Jose L. Prieto, Carnegie Observatories; and Ondrej Pejcha, Department of Astronomy, Ohio State University, report low-resolution optical spectroscopy (range 370-930 nm, resolution 0.7 nm) and optical photometry of M31N 2010-06a, M31N 2010-06b, and M31N 2010-07a. Spectra were obtained by Prieto with the APO 3.5-m telescope (+ DIS) on July 18 UT. Magnitude measurements were obtained from co-added R-band images taken with the 0.65-m telescope (+ G2CCD-3200) at Ondrejov. The spectrograms are posted at the following website URL: http://users.obs.carnegiescience.edu/jose/novae_m31.pdf. A spectrogram of M31N 2010-06a, taken by Prieto 21 days after its first optical detection by Hornoch, exhibits prominent emission lines of Balmer series, Fe II, and O I (777.4- and 844.6-nm), confirming the object as an "Fe II"-class nova. The FWHM of the H-alpha is 1600 km/s. The following additional R-band magnitudes were measured for M31N 2010-06a by Hornoch: June 29.022 UT, 17.4 +/- 0.1 (P. Zasche); 29.034, 17.35 +/- 0.1 (Zasche); 30.003, 17.05 +/- 0.1 (Hornoch); 30.022, 16.9 +/- 0.1 (Hornoch); July 1.022, 17.25 +/- 0.1 (M. Wolf); 2.997, 17.25 +/- 0.1 (Hornoch and Hornochova); 3.025, 17.1 +/- 0.1 (Hornoch and Hornochova); 4.005, 17.2 +/- 0.1 (Hornoch); 4.031, 17.1 +/- 0.1 (Hornoch); 4.956, 17.1 +/- 0.1 (Hornoch); 7.036, 18.0 +/- 0.15 (Hornoch); 8.060, 17.8 +/- 0.1 (Zasche); 9.011, 17.65 +/- 0.1 (Hornoch and Wolf); 9.035, 17.6 +/- 0.1 (Hornoch and Wolf); 14.050, 17.95 +/- 0.1 (Hornoch, Wolf, and Hornochova); 15.010, 17.95 +/- 0.1 (Hornoch and Wolf); 17.062, 18.05 +/- 0.1 (Hornoch and Hornochova). A spectrogram of M31N 2010-06b, taken by Prieto 21 days after its first optical detection by Hornoch, shows prominent emission lines of Balmer series, Fe II, and O I (777.4-nm and 844.6-nm) as well as emission of Ca II near-IR triplet confirming the object as an "Fe II"-class nova. The FWHM of the H-alpha is 760 km/s. The following additional R-band magnitudes were measured for M31N 2010-06b: June 29.022 UT, 18.9 +/- 0.15 (Zasche); 30.003, 18.8 +/- 0.1 (Hornoch); July 1.022, 18.55 +/- 0.15 (Wolf); 2.997, 17.65 +/- 0.1 (Hornoch and Hornochova); 4.005, 17.8 +/- 0.1 (Hornoch); 4.956, 18.4 +/- 0.15 (Hornoch); 7.036, 19.3 +/- 0.2 (Hornoch); 8.060, 19.4 +/- 0.15 (Zasche); 9.011, 19.4 +/- 0.15 (Hornoch and Wolf); 14.050, 19.5 +/- 0.25 (Hornoch, Wolf, and Hornochova); 15.010, 19.4 +/- 0.15 (Hornoch and Wolf); 17.062, 19.2 +/- 0.15 (Hornoch and Hornochova). A spectrogram of M31N 2010-07a, taken by Prieto 11 days after its first optical detection by Hornoch, shows prominent emission lines of Balmer series, Fe II, O I (777.4-nm and 844.6-nm), and Ca II near-infrared emission triplet with strong P-Cygni absorption features. The FWHM of the H-alpha is 1000 km/s. This suggests that the object is young "Fe II"-class nova. The following additional R-band magnitudes were measured for M31N 2010-07a: July 9.011 UT, 17.45 +/- 0.1 (Hornoch and Wolf); 9.035, 17.35 +/- 0.1 (Hornoch and Wolf); 14.050, 17.75 +/- 0.1 (Hornoch, Wolf, and Hornochova); 15.010, 17.55 +/- 0.1 (Hornoch and Wolf); 17.062, 17.3 +/- 0.1 (Hornoch and Hornochova). Hornoch also reports additional R-band photometry of recent M31 novae as measured by himself from images taken with the 0.65-m telescope at Ondrejov. Magnitudes for M31N 2010-05a (cf. CBETs 2305, 2319, and 2341): June 27.034 UT, 18.2 +/- 0.15 (Hornoch); 28.040, 18.1 +/- 0.1 (Hornoch and P. Hornochova); 29.034, 18.4 +/- 0.2 (P. Zasche); 30.022, 18.55 +/- 0.15 (Hornoch); July 3.025, 18.4 +/- 0.15 (Hornoch and Hornochova); 4.031, 18.6 +/- 0.15 (Hornoch). Magnitudes for M31N 2010-06c (cf. CBET 2343): June 28.014 UT, 17.5 +/- 0.1 (Hornoch and Hornochova); 29.022, 17.45 +/- 0.1 (Zasche); 30.003, 17.65 +/- 0.1 (Hornoch); July 1.022, 17.75 +/- 0.1 (Wolf); 2.997, 18.05 +/- 0.1 (Hornoch and Hornochova); 4.005, 18.3 +/- 0.1 (Hornoch); 4.956, 18.2 +/- 0.15 (Hornoch); 7.036, 18.7 +/- 0.2 (Hornoch); 8.060, 18.55 +/- 0.1 (Zasche). Magnitudes for M31N 2010-06d (cf. CBET 2347): July 2.997 UT, 18.6 +/- 0.15 (Hornoch and Hornochova); 3.025, 18.4 +/- 0.1 (Hornoch and Hornochova); 4.005, 17.7 +/- 0.1 (Hornoch); 4.031, 17.75 +/- 0.1 (Hornoch); 4.956, 17.5 +/- 0.1 (Hornoch); 7.036, 19.2 +/- 0.2 (Hornoch); 8.060, 19.2 +/- 0.15 (Zasche). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2010 CBAT 2010 July 24 (CBET 2391) Daniel W. E. Green