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IAUC 6454: 1996aq; N Sgr 1996

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                                                  Circular No. 6454
Central Bureau for Astronomical Telegrams
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
Phone 617-495-7244/7440/7444 (for emergency use only)

SUPERNOVA 1996aq IN NGC 5584
     S. Nakano, Sumoto, Japan, reports that Masakatsu Aoki,
Tsukioka-cho, Toyama, has discovered a supernova (mag 15.7-16.1) in
NGC 5584 on CCD frames taken on Aug. 17.487 UT with a 0.43-m f/6
reflector.  Aoki measured the position of the supernova:  R.A. =
14h22m22s.73, Decl. = -0 23'24".3 (equinox 2000.0), which is 15"
west and 8" south of the center of NGC 5584.  No star was present
at this position on frames taken by Aoki on Apr. 28, May 14, 19,
and 26 or on frames taken by R. Kushida (Yatsugatake South Base
Observatory) on Apr. 18 and May 24.  R. and Y. Kushida report the
following position end figures and magnitude for SN 1996aq from an
unfiltered CCD frame taken on Aug. 18.444:  22s.72, 23".8, mag 15.0.
     S. Benetti, M. Turatto, and T. Augusteijn, European Southern
Observatory (ESO); L. Reduzzi, Universita di Milano; and A.
Clocchiatti, Cerro Tololo Interamerican Observatory, report that
inspection of a preliminarily-reduced CCD spectrum (range 346-1047
nm, resolution 0.9 nm), obtained on Aug. 19.97 UT with the ESO
1.52-m telescope (+ Boller & Chivens spectrograph), confirms
that SN 1996aq is a supernova of type Ic around maximum.  The
spectrum is dominated by lines (with P-Cyg profile) of Ca II (H and
K + infrared triplet), Fe II, and Na I D.  A relatively strong,
symmetric emission, centered at about 657.4 nm (rest frame), with
FWZI about 12 000 km/s, could be identified with H-alpha.  The O I
777.4-nm emission is still weak in comparison with SN 1994I two days
before maximum (Clocchiatti et al. 1996, ApJ 462, 462).  The
expansion velocity deduced from the minimum of the Ca II lines,
corrected by the recession velocity of 1643 km/s (measured from the
H-alpha of the parent galaxy), is about 15 500 km/s.  Towards the
red end of the spectrum, a weak and broad absorption is present,
which could be the minimum of the P-Cyg profile of He I (1083 nm) at
an expansion velocity of about 21 700 km/s.  Infrared spectroscopic
observations to confirm the presence of hydrogen and helium are
urged.  Magnitudes of SN 1996aq obtained on Aug. 18.98 with the
Dutch 0.9-m telescope are:  V = 14.7, U-B = +0.1, B-V = +0.6, V-R =
+0.2, R-I = 0.0.

     Additional photometry from G. Sostero et al. (cf. IAUC 6453):
Aug. 15.868 UT, V = 11.93, B-V = +1.02, V-R = +0.85, V-I = +1.64;
16.854, 11.81, +1.06, +0.79, +1.59.

                      (C) Copyright 1996 CBAT
1996 August 20                 (6454)            Daniel W. E. Green

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