Central Bureau for Astronomical Telegrams
IAUC 7752: 2001fc, 2001fd, 2001fw,, 2001fy; 2001fe; 2001ff
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Circular No. 7752
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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SUPERNOVAE 2001fc, 2001fd, 2001fw, AND 2001fy
A. V. Filippenko and R. Chornock, University of California at
Berkeley, write: "Inspection of CCD spectra (range 330-1000 nm),
obtained on Nov. 16 UT with the Shane 3-m reflector at Lick
Observatory, reveals that SN 2001fc (IAUC 7741, 7743) is a young
type-II supernova; weak, broad H-alpha emission is visible, but the
spectrum is generally featureless. The red continuum suggests
considerable extinction; on the other hand, the interstellar Na I D
lines are relatively weak, and the object is not unusually dim,
given its NASA/IPAC Extragalactic Database (NED) redshift of 5000
km/s. It is possible that SN 2001fc is a type-IIb supernova like
SN 1987K (Filippenko 1988, A.J. 96, 1941) at an early stage of
development. The spectrum of SN 2001fw (IAUC 7751) also resembles
that of SN 1987K, but with very weak H-alpha emission; its exact
classification (IIb, Ib, or Ic) is uncertain. SN 2001fd (IAUC
7742) is of type II, with strong, broad H-alpha emission; H-beta
and H-gamma exhibit P-Cyg profiles. The spectrum of SN 2001fy
(IAUC 7751), also of type II, looks very similar to that of SN
2001fd but with a bluer continuum."
SUPERNOVA 2001fe IN UGC 5129
T. Matheson, S. Jha, P. Challis, and R. Kirshner, Harvard-
Smithsonian Center for Astrophysics, report that a spectrum (range
370-750 nm) of SN 2001fe (cf. IAUC 7742), obtained by P. Berlind on
Nov. 14.49 UT with the F. L. Whipple Observatory 1.5-m telescope (+
FAST spectrograph), shows it to be a type-Ia supernova near maximum
light. Adopting the NED recession velocity of 4059 km/s for the
host galaxy, the supernova expansion velocity is about 11 200 km/s
for Si II (rest 635.5 nm). The spectral-feature age of the
supernova (Riess et al. 1997, A.J. 114, 722) is 1 +/- 2 days before
maximum light.
Filippenko and Chornock also report that inspection of CCD
spectra, obtained at Lick as above on Nov. 15 UT, reveals that
SN 2001fe is of type Ia, close to maximum brightness.
SUPERNOVA 2001ff IN UGC 4685
Matheson et al. add that a spectrum (range 370-750 nm) of SN
2001ff (cf. IAUC 7743), obtained by Berlind as above on Nov. 14.47
UT, shows it to be a type-II supernova past maximum light.
Adopting the NED recession velocity of 3978 km/s for the host
galaxy, the expansion velocity derived from the minimum of the
H-alpha line is 8400 km/s.
(C) Copyright 2001 CBAT
2001 November 16 (7752) Daniel W. E. Green
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