Central Bureau for Astronomical Telegrams
IAUC 7375: 2000O; 2000H; 1999gi
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Circular No. 7375
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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URL http://cfa-www.harvard.edu/iau/cbat.html ISSN 0081-0304
Phone 617-495-7244/7440/7444 (for emergency use only)
SUPERNOVA 2000O IN MCG +3-31-61
T. Puckett, Mountain Town, GA, reports the discovery of an
apparent supernova (mag 17.1) on an unfiltered CCD frame (limiting
mag 19.2) taken with the Puckett Observatory 0.35-m automated
supernova patrol telescope on Mar. 5.26 UT. The candidate is
located at R.A. = 12h11m15s.58, Decl. = +17o53'32".2 (equinox
2000.0), which is 7".7 east and 14".6 north of the center of MCG
+3-31-61. The new object was also present on an unfiltered CCD
frame taken on Mar. 6.10, but it was not definitely present
(though there was possibly a hint) on a frame taken on Feb. 4.32,
neither does it appear on Palomar Sky Survey images taken on 1990
Mar. 23 (limiting mag about 21.0) and 1950 Apr. 20 (limiting mag
about 20.0).
SUPERNOVA 2000H IN IC 454
S. Benetti, E. Cappellaro, M. Turatto, and A. Pastorello,
Padua, report: "We have obtained two good S/N spectra of SN 2000H
(cf. IAUC 7366, 7367) on Mar. 2.0 and 3.0 UT with the European
Southern Observatory 3.6-m telescope (+ EFOSC2). The spectra
(range 340-1020 nm, resolution 1.5 nm) are now dominated by P-Cyg
lines of He I (447.1, 501.5, 587.6, 667.8, 706.5 nm), from which a
mean expansion velocity of 8000 +/- 1000 km/s is derived. In the
red part of the spectrum, the Ca II infrared triplet is present and
intense, from which an expansion velocity of about 7600 km/s is
derived. At 637.6 nm, there is a deep absorption that we identify
with H-alpha and from which an expansion velocity of about 12~500
km/s is derived. In the blue part of the spectrum, there is a tiny
absorption centered at 472.0 nm, from which (if identified with
H-beta) an expansion velocity of 12~400 km/s is obtained, so
strengthening the hypothesis of the hydrogen presence in the SN
2000H. Given the simultaneous presence of strong He and H, based
on these spectra, the supernova should be probably classified as of
type IIB (a core collapse with very little H left in the ejecta),
possibly similar to SN 1993J. We note also a narrow absorption at
596.6 nm that we attribute to a Na D I interstellar line
originating in the parent galaxy. The relatively large equivalent
width (0.12 nm) suggests that the supernova suffered a reddening of
E(B-V) about 0.16 (Benetti et al., in preparation)."
SUPERNOVA 1999gi IN NGC 3184
Unfiltered CCD magnitudes by S. Yoshida and K. Kadota, Ageo,
Saitama, Japan: 1999 Dec. 19.671 UT, 14.5; 22.657, 14.5; 29.650,
14.5; 2000 Jan. 28.650, 14.5; Feb. 12.483, 14.6; 27.690, 14.7.
(C) Copyright 2000 CBAT
2000 March 6 (7375) Daniel W. E. Green
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