We present high time resolution (1.09 s) photometry of GRB 080210 obtained with ULTRASPEC mounted on the ESO/3.6-m telescope, starting 68.22 min after the burst and lasting for 26.45 min. The light curve is smooth on both short (down to 2.18 s) and long time scales, confirmed by a featureless power spectrum. On top of the fireball power-law decay, bumps and wiggles at different time scales can, in principle, be produced by density fluctuations in the circumburst medium, by substructures in the jet or by refreshed shocks. Comparing our constraints with variability limits derived from kinematic arguments, we exclude under-density fluctuations producing flux dips larger than 1 per cent with time scales delta t > 9.2 min (2 per cent on delta t ...
Aims. In this paper we examine gamma-ray and optical data of GRB 091024, a gamma-ray burst (GRB) wit...
We present the first high resolution (R=20000--45000, corresponding to 14 km/s at 4200A to 6.6 km/s ...
Context: New information on short/hard gamma-ray bursts (GRBs) is being gathered thanks to the disco...
We present high time resolution (1.09 s) photometry of GRB 080210 obtained with ULTRASPEC mounted on...
We present the results of a comprehensive study of the gamma-ray burst 080928 and of its afterglow. ...
Aims. We present optical photometry and spectroscopy of the afterglow and host galaxy of gamma-ray b...
International audienceWe present an analysis of time-resolved optical emissions observed from the ga...
8 pages, 5 figures, 4 tablesNew information on short/hard gamma-ray bursts (GRBs) is being gathered ...
We report UBVRI observations of the optical afterglow of the gamma-ray burst GRB 021004. We observed...
Aims: With this paper we want to investigate the highly variable afterglow light curve and environme...
The long burst GRB 050717 was observed simultaneously by the Burst Alert Telescope (BAT) on Swift an...
Aims. With this paper we want to investigate the highly variable afterglow light curve and environme...
4 pages, to be published in ApJInternational audienceWe present an analysis of time-resolved optical...
We present sequential optical spectra of the afterglow of GRB 010222 obtained 1 day apart using the ...
Context. Afterglows of gamma-ray bursts (GRBs) are simple in the most basic model, but can show many...
Aims. In this paper we examine gamma-ray and optical data of GRB 091024, a gamma-ray burst (GRB) wit...
We present the first high resolution (R=20000--45000, corresponding to 14 km/s at 4200A to 6.6 km/s ...
Context: New information on short/hard gamma-ray bursts (GRBs) is being gathered thanks to the disco...
We present high time resolution (1.09 s) photometry of GRB 080210 obtained with ULTRASPEC mounted on...
We present the results of a comprehensive study of the gamma-ray burst 080928 and of its afterglow. ...
Aims. We present optical photometry and spectroscopy of the afterglow and host galaxy of gamma-ray b...
International audienceWe present an analysis of time-resolved optical emissions observed from the ga...
8 pages, 5 figures, 4 tablesNew information on short/hard gamma-ray bursts (GRBs) is being gathered ...
We report UBVRI observations of the optical afterglow of the gamma-ray burst GRB 021004. We observed...
Aims: With this paper we want to investigate the highly variable afterglow light curve and environme...
The long burst GRB 050717 was observed simultaneously by the Burst Alert Telescope (BAT) on Swift an...
Aims. With this paper we want to investigate the highly variable afterglow light curve and environme...
4 pages, to be published in ApJInternational audienceWe present an analysis of time-resolved optical...
We present sequential optical spectra of the afterglow of GRB 010222 obtained 1 day apart using the ...
Context. Afterglows of gamma-ray bursts (GRBs) are simple in the most basic model, but can show many...
Aims. In this paper we examine gamma-ray and optical data of GRB 091024, a gamma-ray burst (GRB) wit...
We present the first high resolution (R=20000--45000, corresponding to 14 km/s at 4200A to 6.6 km/s ...
Context: New information on short/hard gamma-ray bursts (GRBs) is being gathered thanks to the disco...