Central Bureau for Astronomical Telegrams
IAUC 7793: 2002C; 2001ig
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Circular No. 7793
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html ISSN 0081-0304
Phone 617-495-7440/7244/7444 (for emergency use only)
SUPERNOVA 2002C IN IC 3376
B. Swift and W. D. Li, University of California at Berkeley,
report the discovery by LOTOSS (cf. IAUC 7514) of an apparent
supernova in unfiltered images taken with the Katzman Automatic
Imaging Telescope (KAIT) on Jan. 14.5 (mag 16.7) and 15.5 UT (mag
16.8). SN 2002C is located at R.A. = 12h27m52s.66, Decl. =
+27o00'06".1 (equinox 2000.0), which is 30".6 east and 30".7 north
of the nucleus of IC 3376. A KAIT image taken on 2001 May 27.3
showed nothing at this position (limiting mag about 19.0).
SUPERNOVA 2001ig IN NGC 7424
A. Clocchiatti, Pontificia Universidad Catolica de Chile,
reports on his spectroscopic observations of SN 2001ig obtained on
Jan. 13.0 UT with the European Southern Observatory 3.6-m telescope
(+ dual imager/spectrograph EFOSC2): "A fully reduced spectrum
(336-1030 nm; resolution 0.9 nm) with good signal-to-noise shows
that SN 2001ig is, as expected (cf. Phillips et al., IAUC 7772;
Clocchiatti and Prieto, IAUC 7781), making a transition from type
II initially to type Ib/c now. The spectrum resembles that of SN
1993J some 40 days after shock breakout (Swartz et al. 1993, Nature
365, 232), although the spectrum of SN 2001ig displays stronger Ca
II lines, weaker H and He I lines, and faster expansion velocities.
The H-alpha P-Cyg line shows the characteristic complex shape of
the transitional stage (Filippenko et al. 1994, A.J. 108, 2220).
As expected, the blueshifted minimum is blended with the Si II
635.5-nm line and the redshifted maximum indented by the P-Cyg
profile of the He I 667.8-nm line. The positions of blueshifted
minima, proposed line identifications, and resulting approximate
expansion velocities (assuming a recession velocity of 942 km/s for
NGC 7424, from the NASA Extragalactic Database) are: 380 nm, Ca II
(H and K), 12 000 km/s; 469 nm, H-beta, 11 900 km/s; 478 nm, He I
(492.1 nm), 9800 km/s; 487 nm, He I (501.5 nm), 10 000 km/s;
570 nm, He I (587.6 nm, blended with Na I D), 10 000 km/s; 628 nm,
H-alpha (blended with Si II 635.5-nm), 14 100 km/s; 647 nm, He I
(667.8 nm), 10 600 km/s; 830 nm, Ca II (849.8, 854.2, and 866.2 nm),
22 500 km/s. The O I 777.4-nm line is also detected, with a
blueshifted minimum near 760 nm. The center of the profile cannot
be determined, since it is severely blended with a strong telluric
absorption band. Observations of this strange supernova are urged,
since its solar elongation is now getting very small."
(C) Copyright 2002 CBAT
2002 January 16 (7793) Daniel W. E. Green
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