Central Bureau for Astronomical Telegrams
IAUC 7583: 2001U; 2001R; 2001S; (20000) 2000 WR_106
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Circular No. 7583
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)
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SUPERNOVA 2001U IN NGC 5442
M. Schwartz, Cottage Grove, OR; and W. D. Li, University of
California at Berkeley, on behalf of LOTOSS (cf. IAUC 7514), report
the discovery of an apparent supernova (mag about 17.7) on an
unfiltered image taken with the 0.5-m Tenagra III telescope on Feb.
15.5 UT (confirmed at mag about 17.3 on an earlier KAIT image taken
on Feb. 3.5). SN 2001U is located at R.A. = 14h04m42s.94, Decl. =
-9 42'29".7 (equinox 2000.0), which is 4".7 west and 18".7 north of
the nucleus of NGC 5442. A KAIT image taken on 2000 July 2.3
showed nothing at this position (limiting mag about 19.0).
SUPERNOVA 2001R IN NGC 5172
T. Matheson, S. Jha, P. Challis, and R. Kirshner, Harvard-
Smithsonian Center for Astrophysics, report that a spectrum of SN
2001R (cf. IAUC 7579), obtained by M. Calkins on Feb. 16.47 UT with
the Mt. Hopkins 1.5-m telescope (+ FAST spectrograph), shows a
continuum with well-defined P-Cyg lines of hydrogen, sodium, and
iron, consistent with the plateau phase of normal type-II
supernovae after maximum light. Adopting the NED recession
velocity of 4030 km/s for NGC 5172, the expansion velocity derived
from the minimum of the H-beta line is about 2500 km/s."
SUPERNOVA 2001S IN UGC 5491
Matheson et al. also report that a spectrum of SN 2001S (cf.
IAUC 7580), obtained by Calkins as above on Feb. 16.32 UT, shows it
to be a type-II supernova near maximum light. The spectrum
consists of a blue continuum with superposed P-Cyg lines of
hydrogen and Ca II. Adopting the NED recession velocity of 9100
km/s for the host galaxy, the expansion velocity derived from the
minimum of the H-beta line is about 9000 km/s.
(20000) 2000 WR_106
T. L. Farnham, University of Texas, writes: "R- and V-band
CCD photometry of (20000), obtained at the McDonald Observatory
2.1-m telescope on Jan. 24-27, shows a single-peaked rotational
lightcurve with a probable period of 3.17 hr, though 2.78 and 3.67
hr cannot be ruled out. The 0.5-mag amplitude suggests that one
hemisphere reflects at least 60 percent more light than the other.
Less likely (with diameter about 900 km; cf. IAUC 7554), the
lightcurve could be double-peaked with a 6.34-hr period, which
would imply that (20000) has an axial ratio a/b >= 1.6."
(C) Copyright 2001 CBAT
2001 February 16 (7583) Daniel W. E. Green
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