Central Bureau for Astronomical Telegrams
IAUC 8521: 2005bx; 2005bf; GRB 050502
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Circular No. 8521
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 2005bx IN MCG +12-13-19
D. Rich, Hampden, ME, reports his discovery of an apparent
supernova (mag about 17.8) on unfiltered CCD frames taken with a
0.31-m reflector on Apr. 27.10 and 30.08 UT. The new object is
located at R.A. = 13h50m24s.95, Decl. = +68o33'19".4 (equinox
2000.0), which is about 1".5 west and 2".4 north of the center of
MCG +12-13-19. Nothing is visible at this location on CCD frames
taken by Rich on Feb. 28.20 and Apr. 11.08 (limiting mag about
18.6) or on Palomar Digital Sky Survey images from 1993 and 1996
(limiting red and blue magnitudes fainter than 19.0).
SUPERNOVA 2005bf IN MCG +00-27-5
L. Wang, Lawrence Berkeley National Laboratory; and D. Baade,
European Southern Observatory (ESO), on behalf of the collaboration
on supernova polarimetry program, report that the type-Ic supernova
2005bf (IAUC 8507, 8520) was observed at the ESO's Very Large
Telescope (+ FORS1; range 323-840 nm; resolution 0.26 nm/pixel) in
polarimetry mode on Apr. 30. Preliminary inspection of the spectra
indicates a transition to a type II-or type-Ib supernova. Assuming
a recession velocity for the host galaxy of 5670 km/s (Falco et al.
1999, PASP 111, 438), conspicuous lines from He I 501.6-, 587.6-,
667.8-, and 706.5-nm are observed at velocities around 6200 km/s.
The observations also show strong lines of Ca II H and K and the Ca
II infrared triplet at velocities around 10000 km/s. An absorption
line is detected at 624.8 nm -- which, if identified with the Si II
635.5-nm line, gives an expansion velocity of about 5000 km/s; the
same line, however, can be identified as H_alpha at a velocity of
14400 km/s. Similarly, absorption features are observed at 413.9
and 463.4 nm, which can be identified with H_gamma and H_beta,
respectively, at a velocity of 14000 km/s. A blend of Fe II 516.0-
nm and Fe III 515.6-nm is also present in the spectra, at velocity
around 5200 km/s. The supernova shows polarized spectral features
in excess of 2 percent across some spectral lines. Observations at
all wavelengths are strongly encouraged.
GRB 050502
D. T. Durig, University Of The South, measures GRB 050502 (cf.
GCN 3322, 3325, 3327) at R.A. = 13h29m46s.31, Decl. = +42o40'27".2
(equinox 2000.0); approximate CCD V magnitudes: May 2.179 UT,
19.8; 2.182, 20.8; 2.186, 20.3; 2.197, 20.9; 2.201, 21.4; 2.208,
21.0; 2.264, 21.5; 2.264, 22.0.
(C) Copyright 2005 CBAT
2005 May 2 (8521) Daniel W. E. Green
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