Central Bureau for Astronomical Telegrams
IAUC 7784: 1999gw; 2001iq, 2001ir
The following International Astronomical Union Circular may be linked-to from your own Web pages, but must not otherwise be redistributed (see these notes on the conditions under which circulars are made available on our WWW site).
Read IAUC 7785
.dvi or
.ps format.
Circular No. 7784
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 1999gw IN UGC 4881
G. Cresci, Universita degli Studi, Florence; F. Mannucci,
Consiglio Nazionale delle Ricerche, Florence; R. Maiolino and M.
Della Valle, Osservatorio Astrofisico di Arcetri, Florence; and F.
Ghinassi, Telescopio Nazionale Galileo (TNG), report the discovery
of an apparent supernova during a campaign of near-infrared
monitoring of luminous infrared galaxies. SN 1999gw was discovered
at mag 17.8 in a K_s-band image obtained on 1999 Dec. 16.15 UT with
the TNG (+ ARNICA), when compared with an image taken on 2001 Aug.
2.15 with the same telescope (+ NICS). SN 1999gw is located at
R.A. = 9h15m54s.7, Decl. = +44o19'55" (equinox 2000.0), which is
3".5 north of the K_s nucleus A of UGC 4881 (uncertainty on
relative position about 0".4). An additional K_s-band image taken
on 2000 Jan. 26.1 with the TNG (+ ARNICA) shows SN 1999gw at K_s =
18.4.
SUPERNOVAE 2001iq AND 2001ir
R. Chornock and A. V. Filippenko, University of California,
Berkeley, report that inspection of uncalibrated CCD spectra (range
330-1000 nm) obtained on 2001 Dec. 23 UT with the Keck-I telescope
reveals that SN 2001iq (IAUC 7780) is of type Ia and near maximum
brightness. SN 2001ir (IAUC 7781) is of type IIn; the spectrum is
dominated by relatively narrow hydrogen Balmer emission lines.
T. Matheson, S. Jha, P. Challis, and R. Kirshner, Harvard-
Smithsonian Center for Astrophysics, report that a spectrum (range
370-750 nm) of SN 2001iq, obtained by M. Calkins on 2001 Dec. 23.08
UT with the Mt. Hopkins 1.5-m telescope (+ FAST spectrograph),
shows it to be a reddened type-Ia supernova near maximum light. A
recession velocity of 5575 km/s for the host galaxy is derived from
narrow emission lines superposed on the spectrum of SN 2001iq; the
supernova expansion velocity is about 11 600 km/s for Si II (rest
635.5 nm). The spectral-feature age (cf. IAUC 7774) of SN
2001iq is 1 +/- 2 days before maximum light. The spectrum shows
strong narrow Na I D absorptions at zero velocity (0.13 nm
equivalent width) and at the velocity of the host galaxy (0.36 nm
EW). The Schlegel et al. (1998, Ap.J. 500, 525) dust maps indicate
a Galactic reddening of E(B-V) = 0.14. Also, the overall shape of
the spectrum declines toward the blue, implying that SN 2001iq is
heavily extinguished by dust. A spectrum of SN 2001ir, obtained by
Calkins on Dec. 24.38 UT, shows it to be a type-IIn supernova, with
strong H Balmer emission lines superposed on a nearly featureless
blue continuum.
(C) Copyright 2002 CBAT
2002 January 8 (7784) Daniel W. E. Green
Read IAUC 7785
.dvi or
.ps format.
Our Web policy. Index to the CBAT/MPC/ICQ pages.
