Central Bureau for Astronomical Telegrams
IAUC 7724: 2001en; 2001el
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Circular No. 7724
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 2001en IN NGC 523
D. Hutchings 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 Sept. 26.5 (mag about 17.5)
and 27.3 UT (mag about 17.0). SN 2001en is located at R.A. =
1h25m22s.90, Decl. = +34o01'30".5 (equinox 2000.0), which is 6".4
east and 2".8 south of the eastern nucleus of NGC 523. An
unfiltered KAIT image taken on Sept. 20.4 showed nothing at this
positon (limiting mag about 19.5).
SUPERNOVA 2001el IN NGC 1448
L. Wang and D. N. Kasen, Lawrence Berkeley National Laboratory
(LBNL); D. Baade, European Southern Observatory (ESO); C. Fransson,
Stockholm Observatory; D. A. Howell, LBNL; P. Hoeflich, University
of Texas; P. Lundqvist, Stockholm Observatory; P. E. Nugent, LBNL;
and J. C. Wheeler, University of Texas, communicate: "High-quality
spectropolarimetry (range 417-860 nm; spectral resolution 1.27 nm
and 0.265 nm/pixel) of SN 2001el was obtained with the ESO Very
Large Telescope UT3 (+ FORS1) on Sept. 26 UT. The spectra confirm
(cf. IAUC 7723) that this is a type-Ia supernova before maximum,
with a normal spectrum similar to that of SN 1994D except for a
strong double-troughed absorption feature around 800.0 nm (FWHM
about 22 nm). The absorption dips of Si II (635.5, 564.0 nm) and
Fe II (492.4, 516.9 nm) all show velocities of about 10 000 km/s.
The supernova was polarized at a level of 0.9 percent (uncorrected
for interstellar polarization), with clearly polarized features
across several of the spectral lines. Ca II lines are present in
the spectrum at a velocity comparable to that of the Si II 635.5-
nm feature but are much weaker than the absorption feature at 800.0
nm. It is possible that the 800-nm feature is a second component
of high-velocity Ca II, as suggested by Hatano et al. (1999, Ap.J.
525, 881) to explain a similar (but much weaker) feature in SN
1994D. If identified with Ca II, the feature would be due to a
detatched shell/clump with a velocity range from 20 000 to 26 000
km/s. The 800.0-nm feature also shows a significantly higher
degree of polarization than other spectral lines."
(C) Copyright 2001 CBAT
2001 September 28 (7724) Daniel W. E. Green
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