Central Bureau for Astronomical Telegrams
IAUC 7090: 1999E; 1998fa; 1998ez
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Circular No. 7090
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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Phone 617-495-7244/7440/7444 (for emergency use only)
SUPERNOVA 1999E IN ANONYMOUS GALAXY
A. V. Filippenko, D. C. Leonard, and A. G. Riess, University
of California at Berkeley, report: "A spectrum (range 510-880 nm)
obtained on Jan. 19 UT with the Keck-II telescope reveals that SN
1999E (cf. IAUC 7089) is a very unusual type-IIn supernova at
redshift 0.025. Besides the strong, relatively narrow H-alpha
emission line on top of a broader base, there are very broad (FWHM
about 40 nm) emission bumps centered near 560, 640, 755, and 875
nm. The spectrum differs from that of any other supernova ever
examined by the authors."
S. Jha, P. Garnavich, P. Challis, and R. Kirshner, Harvard-
Smithsonian Center for Astrophysics, write: "A spectrum of SN
1999E, obtained by P. Berlind on Jan. 19.5 UT with the Whipple
Observatory 1.5-m telescope (+ FAST spectrograph), displays strong,
narrow (FWHM 370 km/s) H-alpha emission superimposed on a broad
(FWHM 7000 km/s) base. Weak emission from H-beta is also present.
A strong interstellar Na I D absorption feature (equivalent width
0.1 nm) from the host galaxy provides a recession velocity of 7800
km/s. These features suggest that the supernova is of type IIn,
and significantly reddened. One peculiarity is a broad (FWHM
18 000 km/s), unidentified absorption feature observed at 597 nm,
not typically seen in type-IIn supernovae. The supernova is quite
luminous; for V = 16 as reported by Perez et al. (IAUC 7089) and
H_0 = 65 km sE-1 MpcE-1, the absolute magnitude is M_V = -19.4.
Given the reddening, the intrinsic luminosity of the supernova is
likely significantly brighter."
SUPERNOVA 1998fa IN UGC 3513
Filippenko et al. also report that a spectrum (range 510-880
nm) obtained on Jan. 19 UT with the Keck-II telescope, in
comparison with previous spectra, reveals that SN 1998fa (cf. IAUC
7073, 7077) is actually an unusual 'type-IIb' supernova like SN
1987K (Filippenko 1988, A.J. 96, 1941) and SN 1993J (Filippenko et
al. 1993, Ap.J. 415, L103): lines of He I with P-Cyg profiles have
emerged.
SUPERNOVA 1998ez IN ANONYMOUS GALAXY
Filippenko et al. further report that a spectrum obtained as
above on Jan. 20 UT reveals that SN 1998ez (cf. IAUC 7070) is of
type II at redshift 0.07; H-alpha emission is visible on a mostly
featureless continuum.
(C) Copyright 1999 CBAT
1999 January 20 (7090) Daniel W. E. Green
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