Central Bureau for Astronomical Telegrams
IAUC 8250: GRB 031203; C/2002 O7
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Circular No. 8250
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)
GRB 031203
P. van Dokkum, Yale University; J. S. Bloom, Harvard-
Smithsonian Center for Astrophysics; and C. Bailyn, B. Cobb, and M.
Buxton, Yale University, report further analysis of SMARTS-
consortium data on GRB 031203 (cf. GCN 2463) obtained between Dec.
4.125 and 4.258 UT. The summed images reveal no source in I or J
(upper magnitude limits I = 23 and J = 21.0) at the Rapid-Eye-Mount
(REM) robotic-telescope position from La Silla (cf. GCN 2466). A
faint source with J = 20.5 +/- 0.5, undetectable in I, is found
2".5 from the REM position at R.A. = 8h02m29s.78, Decl. =
-39o51'07".1 (equinox 2000.0) +/- 0".4 (1 sigma; found from
astrometric tie to 2MASS). No other source is found within 4".5 of
the REM position. The J-band data were obtained starting at Dec.
4.180 (essentially contemporaneous with the REM observations),
while the I-band images span the entire three hours of observation.
Taking the REM and SMARTS photometry at face value, it is found
that the source has the characteristics of a J 'dropout',
suggesting a redshift of z > 9 (formally z >/= 11). Models
assuming extreme extinction in the host galaxy cannot reproduce the
observed spectral energy distribution (see
http://www.astro.yale.edu/dokkum/GRB031203.html). There are many
caveats, and the nature of this source is still highly uncertain.
Nevertheless, as this is a potential discovery of the highest
redshift source known, the authors encourage the community to
obtain additional near-infrared photometry and (particularly) near-
infrared spectroscopy of this object.
COMET C/2002 O7 (LINEAR)
M. Mattiazzo, Wallaroo, South Australia, reports that a CCD
image taken by himself on Sept. 27.8 UT showed that this comet had
apparently disrupted, revealing only a diffuse sunward-pointing
'antitail' of debris. Requests from the Central Bureau were sent
to several observers at the time, seeking confirmation and
additional details. Nothing further was received. But now, G. P.
Tozzi (Istituto Nazionale di Astrofisica, Arcetri), along with H.
Boehnhardt, O. R. Hainaut, F. Selman, I. Saviane, M. Pizarro, G.
Roman, and F. Labrana, report that they searched for the comet on
Dec. 3 (when its predicted total magnitude was about 10) with
several telescopes at the European Southern Observatory, including
the 2.2-m reflector (R filter), the New Technology Telescope (+ JHK
filters), and the 3.6-m reflector (+ VRi filters); the comet could
not be detected to a limiting magnitude of R about 20.5 within an
area 30' x 30' centered at its predicted position.
(C) Copyright 2003 CBAT
2003 December 4 (8250) Daniel W. E. Green
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