GRB 031111, GRB 031111A

A.Piccioni, C.Bartolini, A.Guarnieri (Bologna University),
 P.Ferrero and G.Pizzichini,(IASF-CNR, Sezione di Bologna)
 and J. Casares (IAC, Tenerife) report:
 
 During the nights Nov 13, 14 and 15, 2003 we observed the error box
 of GRB031111 (Hete burst H2925, Hurley et al., GCN #2443
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 ) in R band
 with the 1m ESA OGS telescope (operated on the island of Tenerife by
 Instituto de Astrofisica de Canarias at the Observatorio del Teide),
 and the IAC CCD camera.
 The initial HETE-WXM field was divided in 9 overlapping subfields.
 With the exception of about 7% of the area at the corners, the full
 final HETE-IPN error box was observed.
 The images intersecting the error box were selected, and we obtained:
 
 13 images x 600 sec on Nov. 13.14 UT (mean epoch)  
 12 images x 600 sec on Nov. 14.16 UT (mean epoch)
  5 images x 600 sec on Nov. 15.04 UT (mean epoch)
 
 Our coadded images of subsequent nights attained just the limit of
 POSS-II, and by comparison we can state that no new object is present.
 Within the same limit and on a time scale of 3 days we do not detect
 any variable object with amplitude > 0.3 mag.
 A few selected images, the observation log and a short comment are
 available in our public account; the coordinates to login (only by ssh
 or sftp) are:
 
        hostname  ermione.bo.astro.it
        username  publicGRB
        password  GRB_bo
        directory GRB031111

 This message may be cited.

Martin Jelinek, Petr Kubanek, Martin Nekola,  Rene Hudec & BART team,
Astronomical Institute Ondrejov, report: 

 
Robotic system BART (Ondrejov Observatory) observed the error box of
GRB031111A (HETE 2924) using its two WF cameras only 30s after receiving
the coordinates.  Overall time since GRB was 70 minutes. Most of the
obtained images were overexposed due to nearby moon, but at images taken
at 2003 Nov 11, 3h20, 3h56, 4h02, 4h08 and 4h14 after burst, no new object
in comparison with GSC was identified; we estimate the limiting magnitude
I about 13 within the combined HETE/IPN error box (cf. GCN 2443
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 ). 

The corresponding image is posted at
http://lascaux.asu.cas.cz/~mates/031111A.jpg

A. M. Soderberg and D. A. Frail (NRAO) report on behalf of a larger
collaboration:

"Using the VLA at 4.9 GHz, we imaged the entire IPN error box
(GCN#2443
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 ) of GRB 031111 (HETE Trigger 2924) on November 14.52 UT
with the Very Large Array. The typical rms noise on the image was
was 77 uJy.  We detect no sources greater than 5 sigma inside the
error region. No further observations are planned."

J. Silvey, D. Allen, R. Canterna (U. of Wyoming) and P.A. Price
(IfA) report on behalf of the FUN GRB collaboration:

We observed the error box of GRB 031111 (Hurley et al., GCN #2443
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 ) with
the RBO 0.6m telescope.  Exposures consisted of 28 individual 300 sec
exposures in I-band under cloudy conditions.  Our images cover an
estimated 98% of the error box at a mean epoch of 2003 Nov 13.2 UT (1.5
days after the GRB), down to an estimated limiting magnitude of R ~ 18.5
mag (on comparison with USNO-A2.0).  We do not detect any optical
afterglow candidate on visual comparison with the DSS 2 N plate.

No further observations of this GRB are planned.

This message may be cited.

S. Fern�ndez-Acosta (IAC, Tenerife), S. Guziy, V. Casanova,
A. de Ugarte, J. Gorosabel and A. J. Castro-Tirado (IAA-CSIC,
Granada), report:

"We have obtained a mosaic of images (3 fields) covering the
entire IPN error box for GRB 031111 (Hurley et al. GCN 2443
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 )
with the 0.8-m IAC80 telescope at Observatorio del Teide starting
on Nov 13.07 UT (31.7-h after the GRB). None of the co-added
images (4 x 600-s exposure time for each field) reveals any new
(or strongly variable source) when comparing with the Digital
Sky Survey (II epoch)".

K. Hurley and T. Cline, on behalf of the Ulysses and HETE GRB teams,

A. von Kienlin, G. Lichti, and A. Rau, on behalf of the INTEGRAL
SPI-ACS GRB team, and

G. Ricker, J-L Atteia, N. Kawai, D. Lamb, S. Woosley, J. Doty, R.
Vanderspek, J. Villasenor, G. Crew, G. Monnelly, N. Butler, J.G.
Jernigan, A. Levine, F. Martel, E. Morgan, G. Prigozhin, J. Braga, R.
Manchanda, G.  Pizzichini, Y. Shirasaki, C. Graziani, M. Matsuoka, T.
Tamagawa, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi,
T. Tavenner, T.  Donaghy, M. Boer, J-F Olive, and J-P Dezalay, on
behalf of the HETE GRB team, report:

Ulysses, INTEGRAL (SPI-ACS) and HETE (H2924: FREGATE and WXM) observed this
burst at 60313 seconds.  Its position was reported in a GCN Notice on
November 11 at 17:55:09.

As observed by Ulysses, it had a duration of approximately 10 seconds,
a 25-100 keV fluence of approximately  2.1E-06 erg/cm2, and a peak flux
of approximately  1.1E-06 erg/cm2 s over 0.50 seconds.  These numbers
are subject to more than the usual amount of uncertainty, as the
background on Ulysses was about 3 times the normal rate due to solar
protons.

We have triangulated it to a preliminary annulus centered  at RA,
Decl(2000)= 351.380, -16.219 degrees, whose radius is 86.229 +/-  0.012
degrees (3 sigma).  This intersects the WXM error box to form an
error box whose coordinates are:

     RA(2000)     DEC(2000)
      71.830      17.934
      71.792      17.969
      71.736      18.204
      71.697      18.238

The combined WXM/IPN error box area is ~24 sq. arcmin., or ~75
times smaller than the WXM-only error box.  A map has been posted
at ssl.berkeley.edu/ipn3/031111.  This error box may be 
improved.