Central Bureau for Astronomical Telegrams
IAUC 7481: 2000da; 2000db; 2000de; C/2000 N2
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Circular No. 7481
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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SUPERNOVA 2000da IN UGC 5
A. Pastorello, E. Giro, G. Altavilla, and S. Benetti, Padua
Astronomical Observatory, report that inspection of a partially
reduced, noisy CCD spectrogram (range 325-752 nm; resolution 1.7
nm) obtained with the Asiago 1.8-m telescope (+ Afosc), on Aug.
23.03 UT reveals that SN 2000da (cf. IAUC 7474) is a type-II
supernova caught soon after maximum light. The spectrum is
dominated by a blue continuum and a broad and slightly asymmetric
H-alpha emission (FWHM about 9500 km/s). H-beta and Fe II lines
show instead well-developed P-Cyg profiles, and an expansion
velocity of about 7800 km/s is derived from the minimum of H-beta
absorption.
SUPERNOVA 2000db IN NGC 3949
Pastorello et al. also report that preliminary inspection of a
partially reduced CCD spectrogram (range 325-752 nm; resolution 1.7
nm), obtained as above on Aug. 22.82 UT, shows that SN 2000db (cf.
IAUC 7475) is a type-II supernova, several weeks after outburst.
Strong P-Cyg lines of H, Fe II (multiplets 40 and 42), Sc II, Na I
(D), and Ba II are superimposed on a relatively red continuum. The
expansion velocity deduced from the minimum of H-alpha line is
about 7300 km/s.
K. Hornoch, Lelekovice, Czech Republic, reports that his CCD
R-band photometry (0.35-m reflector; comparison stars GSC 3452.1250
and 3452.1219) of SN 2000db shows that its brightness decreased
linearly by about 0.013 mag/day between Aug. 14.84 and 20.82 UT.
SUPERNOVA 2000de IN NGC 4384
Altavilla, Pastorello, Benetti, M. Turatto, and Giro also
report that the inspection of a preliminarily reduced spectrum
(range 325-750 nm; resolution 1.7 nm) taken by C. Tappert with the
Asiago 1.8-m telescope (+ Afosc) on Aug. 23.85 UT, indicates that
SN 2000de (cf. IAUC 7478) is a type-Ib supernova, 2-3 weeks after
maximum light. The spectrum shows a red continuum and the
following strong P-Cyg lines of He I: 587.6 (dominant), 667.8, and
706.5 nm. The average expansion velocity deduced from the minima
of He I lines is about 7500 km/s.
COMET C/2000 N2 (SOHO)
Addendum. On IAUC 7459, it should be added that P. Shkreby
also independently found C/2000 N2 in real-time SOHO website data.
(C) Copyright 2000 CBAT
2000 August 24 (7481) Daniel W. E. Green
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