Central Bureau for Astronomical Telegrams
IAUC 7107: 1998ee; 1999Z
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 7108
.dvi or
.ps format.
Circular No. 7107
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)
BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html ISSN 0081-0304
Phone 617-495-7244/7440/7444 (for emergency use only)
SUPERNOVA 1998ee IN ANONYMOUS GALAXY
F. Patat, European Southern Observatory (ESO); M. Salvo,
Padova University; and A. Pizzella, ESO, report on their
observations of SN 1998ee (cf. IAUC 7030) with the ESO 1.5-m
telescope (+ Boller & Chivens spectrograph; range 320-1000 nm,
resolution 1.2 nm) on Feb. 8.19 UT at La Silla: "A full reduction
of the CCD spectrogram shows that this is a peculiar type-II
supernova. The only detectable features are H-alpha and H-beta
emissions, superimposed on a slightly blue continuum. The
expansion velocities, deduced from their FWHM, are 5900 and 5400
km/s, respectively. On top of the H-alpha emission, a clear
unresolved P-Cyg profile is visible, possibly accompanied by other
weaker features. The same structure, even though less pronounced,
is present also in the H-beta line. This indicates the probable
presence of a dense expanding medium around the supernova, similar
to what has been seen in SN 1994aj (Benetti et al. 1998, MNRAS 294,
448). The expansion velocity of this material, computed from the
minimum of the absorption through, is about 1000 km/s. The
recession velocity of the parent galaxy, deduced from the
unresolved H-alpha emission, is 14 900 km/s. Assuming that the
supernova was discovered around maximum, when B about 17.5 (IAUC
7030), it reached an absolute B magnitude of -19.3 (H_0 = 65 km
sE-1 MpcE-1), which is definitely brighter than normal type-II
supernovae."
SUPERNOVA 1999Z IN UGC 5608
S. Jha, P. Garnavich, P. Challis, and R. Kirshner, Harvard-
Smithsonian Center for Astrophysics, report that a spectrum of SN
1999Z was taken by M. Calkins on Feb. 9.3 UT with the F. L. Whipple
Observatory 1.5-m telescope (+ FAST spectrograph) and shows it to
be a type-IIn supernova. The supernova exhibits narrow (FWHM < 300
km/s) Balmer emission lines with somewhat broader (FWHM 1600 km/s)
bases. The recession velocity of the host galaxy is 15 100 km/s,
derived using narrow H-alpha emission from a spiral arm. The
supernova emission features are observed at a redshifted velocity
of 15 600 km/s. Concurrent images taken by P. Zhao with the
Whipple Observatory 1.2-m telescope (+ AndyCam) yield an estimated
magnitude V = 17.4.
Corrigendum. On IAUC 7106, line 5, for 3".6 west and 9"
south read 11" west and 2" south
(C) Copyright 1999 CBAT
1999 February 9 (7107) Daniel W. E. Green
Read IAUC 7108
.dvi or
.ps format.
Our Web policy. Index to the CBAT/MPC/ICQ pages.
