[vsnet-outburst 7575] Nova in Oph

[Mike Simonsen]

Another apparent nova. This one in Ophiuchus.


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                                                Electronic Telegram No. 900
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS at CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT at CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html


APPARENT NOVA IN OPHIUCHUS
     S. Nakano, Sumoto, Japan, reports the discovery by Hideo Nishimura
(Miyawaki, Kakegawa, Shizuoka-ken) of a possible nova (mag 10.2) on two
Kodak T-Max 400 films (limiting mag 12) taken on Mar. 19.812 UT using
a Pentax 6x7 camera (+ 200-mm f/4.0 lens), the new object appearing at
R.A. = 17h42m49s, Decl. = -23o40'07' (equinox 2000.0).  Nothing was
visible at this location on a film taken by Nishimura on Mar. 17.82
and earlier survey films since 2005 (limiting mag 11.5-12).  Nakano adds
that K. Kadota (Ageo, Japan) has confirmed the appearance of the new
star at mag 9.8 on an unfiltered CCD exposure taken on Mar. 20.756 with
a 0.25-m f/5 reflector, the object's position end figures measured to be
44s.00, 35".1; Kadota adds that there is no USNO-A2.0 star within 0'.1
of this position (the closest star having position end figures 43s.41,
34".9 and blue mag 18.5, red mag 16.8).  Also, K. Itagaki has confirmed
the new star using 0.30-cm f/7.8 reflector at his Takanezawa station,
his CCD image on Mar. 20.806 yielding mag 9.7 and position end figures
43s.99, 35".0.
     H. Yamaoka, Kyushu University, reports the apparently independent
discovery of this apparent nova by Yuji Nakamura (Kameyama, Mie, Japan)
at mag 10.0 on unfiltered digital-camera images (cf. CBET 834) taken
on Mar. 20.812 UT.  The variable's position was given by Nakamura as
R.A. = 17h42m44s.5, Decl. -23d40'16" (uncertainty +/- 20"); nothing was
detected at this position on an image taken by Nakamura on Mar. 17.825
(limiting mag about 13.0).  Yamaoka notes that a star of mag 12-13 is
located 1' northeast of the new object.
     Following posting on the Central Bureau's unconfirmed-objects webpage,
H. Naito and S. Narusawa, Nishi-Harima Astronomical Observatory, report
that they obtained a low-resolution spectrogram (range 410-670 nm;
resolution 1500 at H_alpha) of this possible nova on Mar. 20.84 UT with the
2.0-m NAYUTA telescope (+ MALLS).  The spectrum shows Balmer-lines having
P-Cyg features and Fe II lines (multiplets 42, 49, 74), suggesting that the
variable is a "Fe II"-type nova.  The FWHMs of the H_alpha, H_beta, and
H_gamma emissions are 920, 810, and 790 km/s, and the displacement of the
P-Cyg absorptions from the Balmer emission peaks is 940, 820, and 830 km/s,
respectively.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2007 CBAT
2007 March 21                    (CBET 900)               Daniel W. E. Green
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Mike Simonsen

American Association of Variable Star Observers
http://aavso.org/
C. E. Scovil Observatory
http://home.mindspring.com/~mikesimonsen/
CVnet Administrator
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