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GCN Circular 2617

GRB 040624: optical observations at TNG and VLT
2004-07-01T14:55:25Z (20 years ago)
Daniele Malesani at SISSA-ISAS,Trieste,Italy <>
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 

We appreciate the efforts made at the TNG and at the VLT (where part of 
the observations were conducted during technical time).

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