Central Bureau for Astronomical Telegrams
IAUC 8303: 2004ak, 2004al,, 2004ap; IRAS 05436-0007
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Circular No. 8303
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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SUPERNOVAE 2004ak, 2004al, AND 2004ap
T. Matheson, P. Challis, and R. Kirshner, Harvard-Smithsonian
Center for Astrophysics, report that a spectrum (range 370-750 nm)
of SN 2004al (cf. IAUC 8297), obtained by P. Berlind on Mar. 13.27
UT with the Mt. Hopkins 1.5-m telescope (+ FAST), shows it to be a
type-II supernova. A narrow H_alpha emission line superposed on
the spectrum of the supernova indicates a recession velocity of
4340 km/s for the host galaxy. The supernova expansion velocity,
derived from the minimum of the H_beta line, is 6300 km/s. A
spectrum of SN 2004ap (cf. IAUC 8300), obtained by Berlind on Mar.
13.25, shows it to be a type-Ia supernova about a week past maximum
light. A spectrum of SN 2004ak (cf. IAUC 8297), obtained on Mar.
14.31, shows it to be a type-II supernova; the spectrum consists of
a very blue continuum with P-Cyg lines of hydrogen and helium.
Adopting the NED recession velocity of 7214 km/s for the host
galaxy, the expansion velocity derived from the minimum of the
H_beta line is 10700 km/s.
IRAS 05436-0007
T. Simon, University of Hawaii; and S. D. Brittain, E. L.
Gibb, and T. W. Rettig, University of Notre Dame, report on a high-
resolution Keck NIRSPEC spectrum of the near-infrared counterpart
to IRAS 05436-0007 (cf. IAUC 8284). The 2-5-micron data (Feb. 27.3
UT) show a substantial amount of cold polar and apolar (cf.
Ehrenfreund et al. 1997, A.Ap. 328, 649) CO ice. Initial model
fits to the ice profiles are consistent with predominantly cold (<
30 K) amorphous water ice and cold, predominantly apolar CO ice
(both have optical depth tau about 0.6). Also present are
broadened emission lines of 12CO (1-0), (2-1), and (3-2), as well
as 13CO, which likely originate from warm gas (a few thousand
degrees K) in an inner accretion disk region (< 1 AU). Narrow
12CO absorption components are superposed on the underlying
emission features. The narrow absorption components, with the same
radial velocity as the emission lines, suggest substantial cold
circumstellar material from a flared disk (cf. Brittain et al.
2004, Ap.J., submitted). In contrast to the findings published on
IAUC 8301, the hydrogen lines are not strongly detected in the
NIRSPEC data. The hot and cold gas surrounding the central star
are typical of a young T-Tau star, but the relatively deep water
and CO ice features together would be unique for the class. Both
absorptions indicate that the underlying star is embedded deeply
within the Orion L1630 cloud and thus at an earlier stage of
evolution, very possibly a class-I object in transition.
(C) Copyright 2004 CBAT
2004 March 14 (8303) Daniel W. E. Green
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