[IAUC] CBET 931: 20070419 : APPARENT NEW NOVA IN SAGITTARIUS

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                                                  Electronic Telegram No. 931
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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APPARENT NEW NOVA IN SAGITTARIUS
     S. Nakano, Sumoto, Japan, reports the discovery by Yukio Sakurai
(Mito, Ibaraki-ken) of a possible nova (mag 10.3) on two 20-s CCD
exposures taken on Apr. 14.777 UT with a Fuji FinePix S2 Pro Digital
camera (+ Nikon 180-mm f/2.8 lens), giving the position for the new
object as R.A. = 18h10m18s.4, Decl. = -18o46'51" (equinox 2000.0).
Sakurai adds that nothing is visible at this location on an image
taken on Apr. 9.8 (limiting magnitude 11.4).  Nakano provides the
following position end figures for his own measurement of Sakurai's
discovery 'jpeg' image (uncertainty perhaps +/- 2"):  18s.47, 52".0.
On Apr. 19.712, Nakano obtained his own unfiltered CCD frames of the
new object (at mag 10.2) with a 0.25-m f/4.8 reflector, providing the
position end figures 18s.19, 50".9 (but apparently involved with a
nearby 12th-magnitude star).  Nakano adds that K. Itagaki (Yamagata,
Japan) obtained an unfiltered CCD image on Apr. 19.745 showing the
new object at mag 9.8 and providing position, with Itagaki measuring
position end figures 18s.27, 52".1; Itagaki adds that the closest
star on the same frame has position end figures 18s.03, 46".1 (mag
12.1).  Neither the USNO catalogue nor the Digitized Sky Survey
indicates any precursor at the position of the new star.
     H. Yamaoka, Kyushu University, writes that, following posting of
this object on the Central Bureau's unconfirmed-objects webpage, K.
Haseda (Toyohashi, Aichi, Japan) has located several prediscovery
images of the new star with a Canon EOS-5D digital camera (+ 120-mm-f.l.
f/3.5 lens), providing the following estimated magnitudes:  Apr. 7.780,
[11.8; 12.792, 11.2; 13.793, 10.8; 14.777, 10.4.


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                         (C) Copyright 2007 CBAT
2007 April 19                    (CBET 931)               Gareth V. Williams