[IAUC] CBET 1196: 20080104 : SUPERNOVA 2007ux

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                                                  Electronic Telegram No. 1196
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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SUPERNOVA 2007ux
     V. Stanishev, Physics Department, Stockholm University; S. Taubenberger,
Max-Planck Institute for Astrophysics; A. Harutyunyan and S. Benetti,
Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova; and A.
Pastorello, Queen's University, report that a spectrum of SN 2007ux (cf. CBET
1187), obtained on Jan. 4.14 UT with the Nordic Optical Telescope (+ ALFOSC;
range 350-900 nm) by A. Somero, confirms the classification on CBET 1189 as
a type-Ia supernova near maximum light.  The spectrum is similar to that of
SN 1986G (cf. IAUCs 4208, 4210, 4215, 4216) around maximum (Phillips et al.
1987, PASP 99, 592), but the Si II 635.5-nm and 597.2-nm absorptions in SN
2007ux are both stronger.  The pseudo-equivalent widths of these two lines
(as defined in Branch at al. 2006, PASP 118, 560) are 13.7 and 5.3 nm,
respectively.  The equivalent width of Si II 597.2-nm is larger than in the
supernovae spectra in Branch et al., and are comparable to the underluminous
1991bg-like type-Ia supernovae.  The ratio of the depth of the two Si II
absorptions (cf. Nugent et al. 1995, Ap.J. 455, L148) is about 0.61 +/- 0.09,
also similar to the 1991bg-like type-Ia supernovae.  The long slit was
oriented so as to pass through the host galaxy's nucleus (3".7 west and
5".4 south of the supernova).  From the Ca II H and K absorptions and
cross-correlation with the Sb-type galaxy template from Kinney et al. (1996,
Ap.J. 467, 38), the recession velocity of the host is measured to be about
9000 km/s.  The blue-shift of the Si II line (635.5 nm) minimum is then
about 10000 km/s.
     Broadband UBVRI photometry of 2007ux was also obtained.  Using point-
spread-function photometry (to minimize the host-galaxy contamination),
the R magnitude of 2007ux was about 17.3 +/- 0.2, calibrated against the R
magnitudes of three stars from the Hubble Space Telescope Guide Star
Catalogue 2.2; this is notably fainter than the brightness of 2007ux on
2007 Dec. 31 (mag 15.7, as reported on CBET 1187).


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                         (C) Copyright 2008 CBAT
2008 January 4                   (CBET 1196)              Daniel W. E. Green