22 February 2010
IAU Electronic Telegram No.2183
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PROBABLE NOVA IN SCORPIUS
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Koichi Nishiyama, Kurume, Fukuoka-ken, Japan; and Fujio Kabashima,
Miyaki-cho, Saga-ken, Japan, report the discovery of a possible nova
(mag 10.5) on two 40-s unfiltered CCD frames (limiting magnitude 12.7)
taken around Feb. 20.857 UT using a 105-mm f/4 camera lens (+ SBIG
STL6303E camera). They confirmed the appearance of the new object at
mag 10.3 on six 10-s unfiltered CCD frames (limiting magnitude 17.4-17.6)
taken around Feb. 21.832 and mag 10.7 on Feb. 22.846 using a Meade 200R
0.40-m f/9.8 reflector (+ SBIG STL1001E camera), from which they measured
the following precise position: R.A. = 17h06m07s.53, Decl. = -37d14'27".4
+/- 0".2 (equinox 2000.0). Nothing is visible at this position on two
past survey frames taken on 2009 Sept. 18.425 (limiting mag 13.6) and Oct.
3.414 (limiting mag 12.3), or on a Digitized Sky Survey (DSS) plate from
1997 Apr. 2.8 (limiting red mag 18.0).
Following posting on the Central Bureau's unconfirmed-objects webpage,
other observers have reported observations of the new variable. R. Kaufman
(Bright, Victoria, Australia, DSLR camera + 200-mm zoom camera lens) writes
that unfiltered, green-channel images taken on Feb. 22.594 show the new star
at mag perhaps 11.4. S. Kiyota (Tsukuba, Japan; remotely using a Global-
rent-a-scope 32-cm reflector + SBIG ST-10XE CCD cmaera located at Moorook,
South Australia) reports position end figures 07s.51, 26".9 and the following
magnitudes: Feb. 22.701, V = 12.03; 22.702, B = 13.09; 22.703, R_c = 10.70;
22.705, I_c = 9.65. Kiyota adds that nothing is visible at this position on
a "SERC.V" Digitized Sky Survey plate (no additional information provided).
E. Guido and G. Sostero also imaged this object remotely through a
0.40-m f/3.8 reflector from the GRAS Observatory at Moorook on Feb. 22.8,
their unfiltered CCD image yielding magnitude about 10.1 and position end
figures 07s.50, 27".7; an animation showing their image with respect to an
archival DSS plate is posted at website URL http://bit.ly/9wAoFN.
NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.
2010 February 22 (CBET 2183) Daniel W. E. Green