[IAUC] CBET 2128: 20100116 : NOVA OPHIUCHI 2010

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                                                  Electronic Telegram No. 2128
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 2010
     S. Nakano, Sumoto, Japan, reports the discovery by Hideo Nishimura
(Miyawaki, Kakegawa, Shizuoka-ken, Japan) of a possible nova (mag 8.4) on
two 13-s frames (limiting magnitude 11.0, measured by Nakano) taken on Jan.
15.857 UT with a Canon EOS 5D Digital Camera (+ Minolta 120-mm f/3.5 lens),
providing the position as R.A. = 17h39m41s, Decl. = -21d39'47" (equinox
2000.0; measured by Nishimura).  Nothing appears at this position on a frame
from Jan. 13.86 (limiting mag about 9.5, assessed by Nishimura) or on frames
taken monthly during 2009 Jan. 29-Nov. 3 (limiting mag 11.0).  However,
Nishimura did identify a faint image on a frame taken on Jan. 14.865,
from which Nakano derives mag 10.1 (and limiting mag 10.6) and position end
figures 41s.3, 54" for the new object; Nakano also measures mag 8.8 and
position end figures 40s.90, 50".5 from Nishimura's discovery image on
Jan. 15.  Additional position end figures and magnitudes forwarded by Nakano
for the presumed nova from unfiltered CCD frames taken by other observers:
Jan. 16.856, 40s.94, 47".9, mag 8.4 (K. Itagaki, Takanezawa station,
Tochigi-ken, Japan, 0.30-m f/7.8 reflector); Jan. 16.860, 40s.97, 47".4, mag
8.2 (K. Kadota, Ageo, Saitama-ken, Japan, 0.25-m f/5 reflector).  Kadota
adds that nothing is visible at this position on a red Digitized Sky Survey
image from 1997 (limiting mag estimated to be 20 by Nakano).  Itagaki has
posted his image at website URL http://www.k-itagaki.jp/images/pn-sgr.jpg.


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                         (C) Copyright 2010 CBAT
2010 January 16                  (CBET 2128)              Daniel W. E. Green