[IAUC] CBET 1286: 20080306 : SUPERNOVA 2008ax IN NGC 4490

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                                                  Electronic Telegram No. 1286
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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SUPERNOVA 2008ax IN NGC 4490
     S. Nakano had sent an e-mail to the Central Bureau of an independent
discovery of 2008ax (cf. CBETs 1280, 1285) by Koichi Itagaki (Teppo-cho,
Yamagata, Japan), but that original e-mail was never received; subsequent
e-mails give the information that follows.  Itagaki's discovery was made on
numerous unfiltered 20-s CCD frames (limiting mag 19.5) taken around Mar.
4.62 UT using a 0.60-m f/5.7 reflector, showing 2008ax at mag 16.1; additional
images from Mar. 4.75 and 4.80 showed the variable to be about 0.1 mag
brighter.  (The announcement of 2008ax via CBET 1280 was issued around Mar.
4.81 UT.)  Itagaki measured 2008ax to be located at R.A. = 12h30m40s.84 +/-
0s.01, Decl. = +41o38'15".4 +/- 0".1 (equinox 2000.0), which is 53" east and
24" south of the center of NGC 4490.  Nothing is visible on Itagaki's earlier
frames (the most recent being taken on 2007 Feb. 27, with limiting mag 19.0)
or on the Digitized Sky Survey.
     R. Arbour, South Wonston, Hants, U.K., writes that his unfiltered CCD
survey image of NGC 4490, taken on Mar. 3.19 UT with a 40-cm f/5 reflector --
only hours prior to the LOSS discovery (cf. CBET 1280) -- showed nothing at
the position of 2008ax to limiting mag 18.5.


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                         (C) Copyright 2008 CBAT
2008 March 6                     (CBET 1286)              Daniel W. E. Green