Central Bureau for Astronomical Telegrams
IAUC 8409: 2004dy, 2004dz, 2004ea, 2004ee, 2004ej, 2004eo; 2004ed, 2004ek
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Circular No. 8409
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)
SUPERNOVAE 2004dy, 2004dz, 2004ea, 2004ee, 2004ej, 2004eo
G. Folatelli, M. Hamuy and N. Morrell, Carnegie Supernova
Project, report that CCD spectra (range 385-910 nm), obtained on
Sept. 14 UT with the Las Campanas du Pont 2.5-m telescope (+ WFCCD
spectrograph), reveal that SN 2004dz (IAUC 8395), SN 2004ee (IAUC
8399) and SN 2004ea (IAUC 8396) are evolved type-Ia supernovae, a
few months past maximum. They confirm the report on IAUC 8404 that
SN 2004dy is a type-II supernova with broad H_alpha, but they
detect a strong He I 5876-nm emission atop a blue continuum, and
this suggests a young supernova. SN 2004ej (IAUC 8405) is of type
II with a prominent H_alpha P-Cyg profile, the velocity inferred
from the absorption minimum of H_beta being 6400 km/s (assuming the
2723 km/s recession velocity from NED database); both the expansion
velocity and the presence of Fe II 516.9-nm suggest that this
supernova exploded 20-30 days ago.
Morrell, Folatelli, and Hamuy add that two spectra of SN
2004eo (cf. IAUC 8406), taken on Sept. 19.02 (range 455-960 nm) and
Sept. 20.01 UT (range 385-920 nm), reveal that this is a type-Ia
supernova displaying the characteristic Si II (635.5, 413.0, and
597.2 nm) and S II (545.4 and 564.0 nm) features. The minimum of
the Si II 635.5-nm line yields expansion velocities of 12100 and
10000 km/s, respectively, on the two nights, assuming the NED host-
galaxy recession velocity of 4707 km/s. Photometric observations
obtained with the 1-m Swope telescope by S. Gonzalez and W.
Krzeminski yield the following B-band magnitudes: Sept. 18.00,
17.59; 18.99, 17.13; 19.99, 16.74; 21.04, 16.47; 22.05, 16.21.
These suggest that SN 2004eo will reach maximum light in the next 3
days or so.
SUPERNOVAE 2004ed AND 2004ek
Further to IAUC 8408, M. Modjaz et al. report that a spectrum
of SN 2004ed (cf. IAUC 8397), obtained by Calkins on Sept. 10.17,
shows it to be a late-time type-II supernova with strong H_alpha
emission, an H_beta P-Cyg profile and other elements in absorption.
Adopting the NED recession velocity of 7500 km/s for the host
galaxy, the expansion velocity derived from the minimum of the
H_beta line is 6200 km/s. A spectrum of SN 2004ek (cf. IAUC 8405),
obtained on Sept. 14.47, shows it to be most probably a young type-
II supernova. The spectrum consists of a featureless and blue
continuum and is similar to an early spectrum of SN 1993J (Matheson
et al. 2000, A.J. 120, 1487).
(C) Copyright 2004 CBAT
2004 September 23 (8409) Daniel W. E. Green
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