Central Bureau for Astronomical Telegrams
IAUC 8015: 2002hx; 2002hw
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Circular No. 8015
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 2002hx IN PGC 23727
J. Graham and W. Li, University of California at Berkeley,
report the LOTOSS (cf. IAUC 7906) discovery of an apparent
supernova (mag about 18.3) on unfiltered KAIT images taken on Nov.
11.5 and 12.5 UT. SN 2002hx is located at R.A. = 8h27m39s.43,
Decl. = -14o47'15".7 (equinox 2000.0), which is 4".2 west and 20".3
south of the nucleus of PGC 23727. A KAIT image taken on Oct. 26.5
showed nothing at this position (limiting mag about 19.5).
SUPERNOVA 2002hw IN UGC 52
M. Hamuy, Carnegie Observatories, writes that a spectrum
(range 320-930 nm) of SN 2002hw (cf. IAUC 8014), obtained on Nov.
11.05 UT with the Las Campanas Baade 6.5-m telescope (+ Boller &
Chivens spectrograph), shows it to be a type-Ia supernova near
maximum light. Adopting the NED redshift of 5257 km/s, the minimum
of the Si II 633.5-nm absorption yields an expansion velocity of
11500 km/s. Na I D absorption at the redshift of the host galaxy
is observed with an equivalent width of 0.26 nm, which suggests
significant reddening.
A. V. Filippenko and R. Chornock, University of California,
Berkeley, communicate: "Inspection of CCD spectra (range 310-1000
nm) obtained on Nov. 11 UT with the Keck I 10-m telescope (+ LRIS)
shows that the object is of type Ia, close to maximum brightness.
Relative to the Si II 615-nm absorption line, the Si II/Ti II
580-nm absorption is stronger than normal, suggesting that the
object might be somewhat subluminous."
T. Matheson, P. Challis, and R. Kirshner, Harvard-Smithsonian
Center for Astrophysics, report that a spectrum (range 370-750 nm)
of SN 2002hw, obtained by P. Berlind on Nov. 11.19 UT with the Mt.
Hopkins 1.5-m telescope (+ FAST), shows it to be a reddened type-Ia
supernova before maximum. Adopting the NASA/IPAC Extragalactic
Database recession velocity of 5257 km/s for the host galaxy, the
supernova expansion velocity is about 11000 km/s for Si II (rest
635.5 nm). The spectral-feature age of the supernova is 4 +/- 2
days before maximum light. The spectrum shows a relatively strong
Na I D absorption at the velocity of the host galaxy (equivalent
width 0.2 nm). The dust maps of Schlegel et al. (1998 Ap.J. 500,
525) indicate a Galactic reddening of E(B-V) = 0.11. In addition,
the overall shape of the spectrum is flat toward the blue, implying
that the supernova is extinguished by dust.
(C) Copyright 2002 CBAT
2002 November 12 (8015) Daniel W. E. Green
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