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IAUC 6442: 1996an; 22P; C/1996 J1

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                                                  Circular No. 6442
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 1996an IN NGC 1084
     S. Nakano, Sumoto, Japan, reports the discovery by Masakatsu
Aoki, Tsukioka-cho, Toyama, of a supernova (mag 14) in NGC 1084,
found on CCD frames taken on July 27.772 UT with a 0.43-m f/5
reflector.  Y. Kushida, Yatsugatake South Base Observatory,
provides the following precise position from Aoki's exposure for SN
1996an:  R.A. = 2h46m00s.83, Decl. = -7o34'20".3 (equinox 2000.0),
which is 15" east and 22" north of the center of NGC 1084.  R.
Kushida (Yatsugatake) reports that a frame taken on 1995 Dec. 21
shows no star at the position of SN 1996an.  SN 1963P also appeared
in NGC 1084.
     S. Benetti, M. Turatto, and G. van de Steene, European
Southern Observatory (ESO), report:  "Inspection of a fully-reduced
CCD spectrogram (range 400-980 nm, resolution 0.7 nm) obtained on
July 30.41 UT with the ESO 1.5-m telescope (+ Boller & Chivens
spectrograph) at La Silla confirms this object as a type-II
supernova, approximately 2 months after explosion.  The spectrum
consists of a multitude of lines with the canonical P-Cyg profiles,
superimposed on a relatively red continuum.  Most of the lines
arises from H I, Ca II, Na I, Ba II, Fe II, O I, and Sc II.  The
expansion velocities deduced from the minima of the most prominent
lines are:  4250 km/s (H-alpha); 4000 km/s (Ca II infrared); 3650
km/s (Na I); 2600 km/s (Ba II); and 3000 km/s (Fe II).  The
recession velocity at the supernova location is 1250 km/s, as
deduced from the narrow H-alpha and [N II] emissions.  A narrow
interstellar absorption of Na I D (measured at 591.8 nm) is
clearly visible."

     Visual m1 and coma-diameter estimates (cf. IAUC 6414):  June
8.97 UT, 7.8, 7' (K. Hornoch, Lelekovice, Czech Republic, 10x80
binoculars); 18.35, 8.5, 4' (R. Keen, Mt. Thorodin, CO, 0.15-m
reflector); July 9.91, 7.8, 10' (M. V. Zanotta, Laino, Italy, 20x80
binoculars); 12.17, 7.6, 7'.2 (J. E. Bortle, Stormville, NY, 20x80
binoculars); 24.53, 8.0, 6' (A. Pearce, Elwood, Vic., Australia,
20x80 binoculars); 27.28, 8.3, 6'.5 (C. E. Spratt, Victoria, BC,
0.20-m reflector).

     Total visual magnitude estimates (cf. IAUC 6418):  June 19.17
UT, 13.3 (A. Hale, Cloudcroft, NM, 0.41-m reflector); July 12.80,
13.1 (H. Luethen, Tivoli, Namibia, 0.25-m reflector); 17.80, 12.9

                      (C) Copyright 1996 CBAT
1996 July 30                   (6442)            Daniel W. E. Green

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