Electronic Telegram No. 2472
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


APPARENT NOVA IN M31:  M31N 2010-09b
     Koichi Nishiyama, Kurume, Japan; and Fujio Kabashima, Miyaki, Japan,
report their discovery of a possible nova (mag 17.3) in M31 on seven 40-s
unfiltered CCD frames (limiting magnitude 19.8) taken around Sept. 30.566 UT
using a Meade 200R 0.40-m f/9.8 reflector (+ SBIG STL1001E camera), as
tabulated below.  An independent discovery has been reported by Guoyou Sun
(Wenzhou, Zhejiang, China) and Xing Gao (Urumqi, Xinjiang, China)
on 60-s unfiltered CCD survey images (limiting mag about 19) taken by Gao
in the course of the Xingming Observation Sky Survey at Mt. Nanshan around
Sept. 30.678 using a 35-cm Celestron C14 Schmidt-Cassegrain telescope at
f/7.5 (the measurements tabulated below are by Sun), adding that nothing is
visible at the same position on images taken on Sept. 9, 10, 11, 15, and 29
(no limiting magnitude given).  T. Yusa, Osaki, Japan, also reports his
confirmation of M31N 2010-09b on unfiltered CCD frames (limiting mag 18.2)
taken on Oct. 1.42, following a request from Kabashima and Nishiyama, using
a 0.30-m f/9.9 Cassegrain telescope (+ SBIG STL-1001E camera), with his
data also tabulated below; he has posted his image at the following website
URL:  http://space.geocities.jp/yusastar77/PNinM31_101001.htm.
Wolfgang Pietsch, Max-Planck-Institut fuer Extraterrestrische Physik,
reports a pre-discovery observation from CCD images obtained with the
robotic 60-cm telescope of the Livermore Optical Transient Imaging System
(cf. CBET 2124), also tabulated below.

 2010  UT          R.A. (2000.0) Decl.      Mag.    Observers
 Sept. 30.412    0 43 45.53  +41 07 54.7    17.7    Pietsch et al.
       30.566    0 43 45.52  +41 07 54.9    17.3    Nishiyama, Kabashima
       30.678    0 43 45.1   +41 07 54.4    17.8    Sun, Gao
 Oct.   1.416    0 43 45.54  +41 07 55.0    16.9    Yusa

Nishiyama notes that M31N 2010-09b is located 690" east and 494" south of the
center of the galaxy M31.  Additional magnitudes for M31N 2010-09b:  1986 Nov.
27, [18.9 (Digitized Sky Survey, red; via Nishiyama and Kabashima); 1993 Oct.
21, [18.4 (DSS, infrared; via Nishiyama and Kabashima); 2010 Sept. 21.570,
[19.2 (Nishiyama and Kabashima); 28.606, [19.2 (Nishiyama and Kabashima);
Oct. 1.516, 16.9 (Nishiyama and Kabashima); 1.564, 16.8 (Nishiyama and
Kabashima).


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2010 CBAT
2010 October 1                   (CBET 2472)              Daniel W. E. Green