[IAUC] CBET 1496: 20080904 : POSSIBLE NOVA IN SCORPIUS

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                                                  Electronic Telegram No. 1496
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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POSSIBLE NOVA IN SCORPIUS
     S. Nakano, Sumoto, Japan, reports the discovery by K. Nishiyama (Kurume,
Fukuoka-ken) and F. Kabashima (Miyaki-cho, Saga-ken) of a bright star (mag
9.5) on unfiltered CCD images obtained on Sept. 2.4594 UT with a 0.40-m f/9.8
reflector, brightening to mag 9.0 on Sept. 3.5119, the variable being located
at R.A. = 17h57m32s.94, Decl. = -30o43'10".0 (equinox 2000.0).  Nothing is
visible at this position on their unfiltered CCD frames taken on Aug. 20.476
(limiting mag 12.8) and 21.470 (limiting magnitude 12.1) using a patrol camera
(+ 105-mm-f.l. f/5.6 lens).  They note nearby USNO-B1.0-catalogue stars at
position end figures 33s.221, 10".56 (red mag 12.7) and 33s.015, 10".39 (red
mag 14.8).  Nakano also reports the independent discovery of this variable
by Yukio Sakurai (Mito, Ibaraki-ken) at mag 9.7 on two survey frames taken
on Sept. 3.437 and 3.438 using a Fuji FinePix S2 Digital Camera (+ Nikon
180-mm-f.l. f/2.8 lens), providing position end figures 33s, 09"; Sakurai
adds that nothing is visible at this position on a frame taken on July 30
(limiting magnitude 12).
     Guoyou Sun, Qufu, Shandong, China; and Xing Gao, Urumqi, Xinjiang, China,
report the independent discovery of this possible nova (mag approximately
10.5) on several 60-s survey images (limiting mag about 13.5) taken by Gao in
the course of the Xingming Observatory Nova Survey around Sept. 2.6095 and
2.6303 UT using a Canon EOS 350D Camera (+ 135-mm-f.l. f/2 lens, at ISO 400),
the new object being approximately located at R.A. = 17h57m32s, Decl.=
-30o43'04" (equinox 2000.0).  Nothing was visible at this position on
images taken on Aug. 14, 20, 21, 30, and 31 (limiting mag presumed to be
about 13.5).
     Following posting on the CBAT unconfirmed-objects webpage, several
other observers have sent observations of this apparent nova.  Unfiltered CCD
300-s images (limiting mag 14.5) taken by D. Chekhovich, S. Korotkiy, and T.
Kryachko with a Canon EOS 350D camera (+ 135-mm-f.l. f/4 lens) at Kazan State
University's Astrotel Observatory (Karachay-Cherkessia, Russia) show the
variable at mag 10.5 on Sept. 2.735 UT and mag 9.5 on Sept. 3.732.  Nothing
is visible at this position on images obtained on Aug. 30.783 (limiting mag
14.5).  Astrometry obtained by the same observers from 10-s CCD images
obtained on Sept. 3.72 with a 8.0-cm f/7.5 ED refractor (+ SBIG ST-2000XM
camera) yields position end figures 32s.91, 10".3.
     E. Guido, G. Sostero, and P. Camilleri write that they observed this
object remotely with a 0.1-m f/5 refractor at Moorook, Australia, on Sept.
3.45 UT, finding the object at unfiltered CCD mag about 9.6 and at position
end figures 32s.93, 10".3.  Nothing is visible on a U.K. Schmidt plate from
1992 June 3 (no limiting magnitude provided), though a nearby field star with
position end figures 32s.95, 08".1 has magnitude about 18.  Their CCD image
is posted at the following website URL:  http://tinyurl.com/5w5e8u.
     C. Jacques and E. Pimentel, Belo Horizonte, Brazil, report that their
30-s unfiltered CCD image on Sept. 3.96 UT with a 30-cm f/3.0 Schimdt-
Cassegrain reflector at CEAMIG-REA Observatory yields mag 8.5 and position
end figures 32s.83, 11".7.  Nothing is visible at this position on a Palomar
Sky Survey image from 1958 Apr. 18 (limiting mag 19.0).


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                         (C) Copyright 2008 CBAT
2008 September 4                 (CBET 1496)              Daniel W. E. Green