Central Bureau for Astronomical Telegrams
IAUC 7511: 2000dw; 2000ds, 2000dt, 2000du, 2000dv; C/1999 Y1
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Circular No. 7511
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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SUPERNOVA 2000dw IN UGC 11955
Y. L. Qiu and J. Y. Hu, Beijing Astronomical Observatory
(BAO), on behalf of the BAO Supernova Survey, report the discovery
of an apparent supernova (mag about 17.5) in unfiltered images
taken on Oct. 17.5 and 20.6 UT with the BAO 0.6-m telescope. The
new object was confirmed by W. D. Li, University of California at
Berkeley, on unfiltered images taken on Oct. 19.2 with the 0.8-m
Katzman Automatic Imaging Telescope. SN 2000dw is located at R.A.
= 22h13m49s.06, Decl. = +39o14'15".1 (equinox 2000.0), which is
1".5 east and 3".3 north of the center of UGC 11955. Photometry is
difficult, as the object is very close to the nucleus of the parent
galaxy. Unfiltered BAO images taken on July 12 (limiting mag about
19.0) showed no star at the position of the new object.
SUPERNOVAE 2000ds, 2000dt, 2000du, 2000dv
A. V. Filippenko and R. Chornock, University of California at
Berkeley, communicate: "Inspection of CCD spectra (range 330-1000
nm) of SN 2000dt (IAUC 7508), obtained on Oct. 24 UT with the Shane
3-m reflector at Lick Observatory, reveal that the object is
probably of type Ib. He I absorption lines are present, but there
is also an unidentified line at rest wavelength 622 nm (possibly
blueshifted C II 658 nm, or perhaps H-alpha, though the
corresponding H-beta line seems absent). SN 2000dv (IAUC 7509) is
also a type-Ib supernova, about 3 months past maximum brightness;
it is starting to enter the nebular phase, but He I absorption is
still present. SN 2000ds (IAUC 7507) is an even older type-Ib (or
-Ic) supernova, perhaps 4 to 7 months past maximum; we prefer the
type-Ib classification because the [Ca II] 732-nm emission has FWHM
approximately 5000 km/s, most consistent with type-Ib supernovae
(Filippenko et al. 1995, Ap.J. 450, L11; Matheson et al. 2001, A.J.,
in press). SN 2000du (IAUC 7509) is a normal type-II supernova;
H-alpha exhibits a classic P-Cyg profile."
COMET C/1999 Y1 (LINEAR)
Total visual magnitude estimates (L = reflector): Aug. 5.00
UT, 13.7 (M. Meyer, Frauenstein, Germany, 0.25-m L); 26.30, 14.2
(A. Hale, Cloudcroft, NM, 0.41-m L); Sept. 8.90, 13.7 (W. Hasubick,
Buchloe, Germany, 0.44-m L); Oct. 6.01, 12.9 (G. Comello, Roden,
The Netherlands, 0.31-m L); 17.79, 12.6 (R. J. Bouma, Groningen,
The Netherlands, 0.25-m L); 23.76, 12.1 (M. Lehky, Hradec Kralove,
Czech Rep., 0.42-m L).
(C) Copyright 2000 CBAT
2000 October 24 (7511) Daniel W. E. Green
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