[IAUC] CBET 1910: 20090817 : NOVA OPHIUCHI 2009

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                                                  Electronic Telegram No. 1910
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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CBAT en CFA.HARVARD.EDU (science)
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NOVA OPHIUCHI 2009
     S. Nakano, Sumoto, Japan; and H. Yamaoka, Kyushu University, report
the discovery by Koichi Itagaki (Teppo-cho, Yamagata, Japan) of a possible
nova (mag 10.0) on his unfiltered CCD survey frames taken on Aug. 16.515 UT
using a 0.21-m f/3 reflector (limiting magnitude 15), the position given as
R.A. = 17h38m19s.68, Decl. = -26d44'14".0 (equinox 2000.0).  Confirming images
(limiting mag 18.5) taken by Itagaki with a 0.60-m f/5.7 reflector on Aug.
16.526 yield mag 10.1 and position end figures 19s.70, 14".0.  Nothing is
visible at this position on Itagaki's frame taken with the 0.21-m reflector
on 2008 June 10.645 (limiting mag 15.0) or on the Digitized Sky Survey (DSS).
K. Kadota (Ageo, Japan) also confirmed the new star on an unfiltered CCD
frame taken on Aug. 16.576 using a 0.25-m f/5 reflector, measuring mag 10.2
and position end figures 19s.70, 13".8 (GSC-ACT catalogue reference stars
for the astrometry).  Kadota adds that the nearest USNO-B1.0-catalogue stars
have position end figures 19s.81, 15".4 (red mag 16), and 19s.88, 13".4 (red
mag 17-18), noting that nothing is visible at the position of the new star
on red DSS images from 1991 and 1996.  Yamaoka writes that there is no object
brighter than mag about 14.0 on a ASAS-3 V-band image (cf. Pojmanski 2002,
Acta. Astron. 52, 397) taken on 2009 Aug. 14.142.  Itagaki further reports
that the new star has faded to mag about 11.1 on Aug. 17.428.
     Following posting on the Central Bureau's unconfirmed-objects webpage,
other observers have reported magnitudes and positions for the presumed
nova.  M. Nissinen and V.-P. Hentunen, Varkaus, Finland, report that images
(limiting mag R = 17.2) obtained remotely with the GRAS4 Epsilon telescope
near Mayhill, NM, U.S.A., on Aug. 17.114 yield mag R = 11.0 and position end
figures 19s.70, 13".7 (USNO-A2.0 catalogue), adding that nothing is visible
at this position on a Palomar Sky Survey DSS image (limiting red mag 20.8).
S. Kiyota, Tsukuba, Japan, reports position end figures 19s.68, 14".0 and the
following magnitudes from images taken remotely with the 30-cm Global
Rent-a-Scope G1 near Mayhill:  Aug. 17.133, B = 13.54; 17.134, V = 11.90;
17.135, R_c = 10.42; 17.137, I_c = 9.36.  L. Elenin reports position end
figures 19s.72, 13".7 (UCAC2 catalogue; RMS 0".6; Astrometrica software) and
the following magnitudes from remotely obtained images using a 35.6-cm
Maksutov-Newton reflector at the Tzec Maun Observatory near Mayhill:  Aug.
17.225, B = 13.67; 17.223, V = 12.43; 17.218, R = 10.78.


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

                         (C) Copyright 2009 CBAT
2009 August 17                   (CBET 1910)              Daniel W. E. Green