GCN Circular 2617
Subject
GRB 040624: optical observations at TNG and VLT
Date
2004-07-01T14:55:25Z (20 years ago)
From
Daniele Malesani at SISSA-ISAS,Trieste,Italy <malesani@sissa.it>
D. Fugazza, P. D'Avanzo, G. Tagliaferri, S. Kalogerakos, S. Campana, G.
Chincarini, S. Covino, A. Cucchiara (INAF-OABr), D. Malesani
(SISSA-Trieste), N. Masetti (IASF-CNR), G.L. Israel, L. Stella
(INAF-OAR), M. Pedani, L. Di Fabrizio (INAF-TNG), M. Petr-Gotzens and
P.M. Vreeswijk (ESO), report on behalf of a larger collaboration:
We observed the field of GRB 040624 (Mereghetti et al., GCN 2613), using
the Italian TNG (with DOLORES) and the ESO VLT-UT1 (with FORS1 and
FORS2). The full error box was imaged in the R filter at several epochs,
starting 13 hours after the burst. The observation log is reported below.
Tel. Instr. UT start t-t0 (d) t_exp (s) seeing R_lim (10 sigma)
---------------------------------------------------------------------
TNG DOLORES 24.90 0.55 2x120 1.2" 22.4
VLT FORS2 24.99 0.64 5x30 0.3" 23.1
VLT FORS2 25.12 0.77 5x30 0.4" 23.1
VLT FORS1 27.98 3.63 5x30 0.7" 22.9
TNG* DOLORES 28.89 4.54 2x120 2.4" 21.5
---------------------------------------------------------------------
*: bad observing conditions.
No observation could be performed on Jun 25 and Jun 26 due to the
proximity of the bright Moon.
No new objects were seen at any epoch when comparing with the DSS
survey, also in agreement with previous reports (Kann et al., GCN 2614;
Gorosabel et al., GCN 2615; Lipunov et al., GCN 2616). We also performed
a systematic analysis looking for variable objects between the different
frames. Both aperture photometry (with DAOPHOT) and image subtraction
(with ISIS) were performed. No variable objects were found using both
approaches.
We appreciate the efforts made at the TNG and at the VLT (where part of
the observations were conducted during technical time).
This message can be cited.