[IAUC] CBET 2398: 20100803 : NO NOVA IN M32 (M32N 2010-07a)

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                                                  Electronic Telegram No. 2398
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 en iau.org; cbatiau en eps.harvard.edu
URL http://www.cfa.harvard.edu/iau/cbat.html


NO NOVA IN M32 (M32N 2010-07a)
     Kamil Hornoch, Astronomical Institute, Ondrejov; Ondrej Pejcha, and
Robert F. Wing, Department of Astronomy, Ohio State University; Ovidiu
Vaduvescu and Andrew Cardwell, Isaac Newton Group of Telescopes; and Jose L.
Prieto, Carnegie Observatories, report their results of photometry and
spectroscopy of the presumed nova announced on CBET 2379.  In view of the
apparent red color of the object and lack of strong H_alpha emission (see
photometric measurements below), Vaduvescu and Cardwell obtained a low-
resolution optical spectrum (range 350-900 nm, resolution 1.3 nm) with the
4.2-m William Herschel Telescope (+ ACAM) at La Palma on July 23.15 UT.  The
spectrum shows TiO absorption bands consistent with an M2 star.  The
luminosity-sensitive features at rest wavelength 649.7 nm and a broad CN
absorption at 795 nm are present, and their strengths suggest a supergiant
luminosity.  There is a narrow (consistent with instrumental profile) and
weak H_alpha emission with equivalent width 0.46 nm.  The radial velocity
of H_alpha emission is -290 +/- 40 km/s, which favors membership in M31
but does not disprove membership in M32.  The implied absolute magnitude is
about M_R = -4.7.
     In addition, they found that M32N 2010-07a is possibly associated with
a rather red object in the catalogue of variable stars from the POINT-AGAPE
survey (An et al. 2004, MNRAS, 351, 1017).  The object with number 95143 has
a period of 258 days and is located at R.A. = 0h42m32s.515, Decl. =
+40o53'36".783 (equinox 2000.0), which is 0".7 east and 0".1 south from the
best position of M32N 2010-07a obtained from the recent images taken by D.
Pinfield, B. Sipocz, and G. Kovacs with the 2.54-m Isaac Newton Telescope
(+ WFC) at La Palma.  Based on the available evidence, they propose that
M32N 2010-07a is a long-period variable star currently slowly declining
from maximum brightness.
     The following additional magnitudes of M32N 2010-07a were measured by
Hornoch from available images:  2010 July 19.186 UT, Sloan r' = 20.20 +/-
0.06 (Pinfield, Sipocz, and Kovacs, 2.54-m Isaac Newton Telescope at La
Palma); 19.191, [H_alpha] = 19.9 +/- 0.15 (Pinfield, Sipocz, and Kovacs);
20.121, [H_alpha] = 19.8 +/- 0.15 (J. Gorosabel, O. Lara Gil, M. Jelinek,
P. Kubanek, and P. Martorell, 1.23-m telescope at Calar Alto); 21.934, R-I
= +0.9 +/- 0.3 (Hornoch and P. Zasche, 0.65-m telescope at Ondrejov);
23.175, Sloan g' = 21.7 +/- 0.2 (Vaduvescu and Cardwell, 4.2-m William
Herschel Telescope at La Palma); 23.177, Sloan r' = 20.29 +/- 0.05
(Vaduvescu and Cardwell); 23.180, Sloan i' = 19.35 +/- 0.02 (Vaduvescu and
Cardwell).


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                         (C) Copyright 2010 CBAT
2010 August 3                    (CBET 2398)              Daniel W. E. Green