Jose Angel Berna

Recent Developments in the BOOTES Experiment

BOOTES, the Burst Observer and Optical Transient Exploring System, is mostly a Spanish‐Czech international collaboration that works to fill the space that there actually exists in the rapid variability Astronomy. It is specially aimed towards the detection and study of the optical transients that are generated in conjunction with the elusive GRBs (Gamma Ray Bursts). Since 1998 BOOTES has provided follow ups for more than 60 of these phenomena with the first of its observatories; the most important results obtained so far are the detection of an OT (Optical Transient) in the GRB 000313 error box and the non detection of optical emission simultaneous to the GRB 010220 event. With the recent inauguration of a second observatory BOOTES multiplies its science capabilities.

Detection of an optical transient following the 13 March 2000 short/hard gamma-ray burst ?

We imaged the error box of a gamma-ray burst of the short (0.5 s), hard type (GRB 000313), with the BOOTES-1 experiment in southern Spain, starting 4 min after the-ray event, in the I-band. A bright optical transient (OT 000313) with I= 9:4 0:1 was found in the BOOTES-1 image, close to the error box (3) provided by BATSE. Late time VRIK 0 -band deep observations failed to reveal an underlying host galaxy. If the OT 000313 is related to the short, hard GRB 000313, this would be the first optical counterpart ever found for this kind of events (all counterparts to date have been found for bursts of the long, soft type). The fact that only prompt optical emission has been detected (but no afterglow emission at all, as supported by theoretical models) might explain why no optical counterparts have ever been found for short, hard GRBs. This fact suggests that most short bursts might occur in a low-density medium and favours the models that relate them to binary mergers in very low-density environments.

Recent Developments at Bootes

A very brief overview of the technological and scientific developments at the Burst Observer and Optical Transient Exploring System is given:

First results from the Burst Observer and Optical Transient Exploring System station 1 (BOOTES-1)

The Burst Observer and Optical Transient Exploring System (BOOTES) is considered as a part of the preparations for ESA’s INTEGRAL satellite, and is currently being developed in Spain, in collaboration with two Czech institutions. It makes use of two sets of wide-field cameras, 240 km apart, and two robotic 0.3-m telescopes. The first observing station (BOOTES-1) is located in Huelva (Spain) and the first light was obtained in July 1998. During the test phase, it has provided rapid follow-up observations with the wide-field cameras for 19 GRBs detected by BATSE aboard CGRO, and narrow-field imaging for 6 bursts. Limiting magnitudes for any GRB optical afterglow are I∼13 and R∼16.5, a few minutes after the events.