Jan Soldan

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.

Search for Gamma Ray Burst Quasi Simultaneous Optical Emission with BOOTES-1

The Burst Observer and Optical Transient Exploring System experiment (BOOTES) has been designed to provide an automatic real time observing response to the detection of Gamma Ray Bursts (GRBs). It achieves such response by using wide field cameras attached to small robotic telescopes and imaging in the B, I and R bands. To date we have obtained images for about 50 events with the Wide Field Camera (WFC), starting, in several ocasions, 3 minutes after the burst commenced. One of the last searches resulted in the detection of an optical transient, candidate to be the optical counterpart of the GR.B 000313, although such relation has not been established to absolute certainty yet.

Optical transient monitor

Although there are several optical GRB follow-up systems in operation and/or in development, some of them with a very short response time, they will never be able to provide true simultaneous (no delay) and pre-burst optical data for GRBs. We report on the development and tests of a monitoring experiment expected to be put into test operation in 1998. The system should detect Optical Transients down to mag 6–7 (few seconds duration assumed) over a wide field of view. The system is based on the double CCD wide-field cameras ST8. For the real time evaluation of the signal from both cameras, two TMS 320C40 processors are used. Using two channels differing in spectral sensitivity and processing of temporal sequence of images allows us to eliminate man-made objects and defects of the CCD electronics. The system is controlled by a standard PC computer.

Optical observations of GRBs: EN, BART, and OMC

We report on the ongoing projects at the Astronomical Institute Ondrejov. The EN (European Fireball Network) is based on 11 photographic stations and has already provided simultaneous optical data for 100 GRB triggers. A summary and discussion of the obtained results are given as well as discussion of detected candidates. The BART (Burst Alert Robotic Telescope) is a 25 cm aperture remotely controlled system in test operation. The OMC (Optical Monitoring Camera), prepared by a wide international collaboration for the INTEGRAL satellite (launch 2001), will also have capability for the detection of optical transients and optical afterglows of GRBs, assuming that their rate is higher than the GRB rate (caused by different beaming).

CCD sky monitoring and burst alert

Two proposals for detection of optical flashes related to ,γ-ray bursts are briefly described. The aim of the first proposal is to develop a reliable monitoring service at optical wavelengths, and the second proposal deals with an automatically working telescope with full remote control via Internet network.

The burst observer and optical transient exploring system (BOOTES)

The Burst Observer and Optical Transient Exploring System (BOOTES) is currently being developed in Spain, in collaboration with the Astronomical Institute at Ondrejov, Czech Republic. It will make use of two sets of wide-field cameras 80 kms apart, and a robotic 25-cm telescope. All the instruments will be placed in Southern Spain. It is expected that BOOTES will provide rapid follow-up observations of GRBs detected with BATSE and HETE, as well as clarify whether optical transients are indeed of cosmic origin.

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.

Optical follow-up observations of locburst GRB locations with OMC test camera

Abstract The test camera of the Optical Monitoring Camera (OMC) experiment for INTEGRAL spacecraft achieving the angular pixel size of 18 arcsec and the field of view 7.5° × 5.1° has been succesfully developed and tested at the Astronomical Institute Ondřejov. The test camera is able to provide imaging down to 15 mag over the whole field of view within one exposure of 300 seconds. Although developed primarily to test the OMC performance and help with software development, this device is ideally suitable for the use as ground-based camera for the sites where Compton Gamma-Ray Observatory BATSE Locburst triggers are followed-up in optical waveband and also for wide-field sky monitoring in general. The low cost of this camera makes it possible to duplicate the system to a number of observing sites. A chart and a corresponding CCD-image for the BACODINE Locburst Position 6368 taken with OMC test camera at Ondřejov observatory are also presented. The image taken 18 hours after the trigger was computer-blinked with the frame taken 30 days later. No optical activity has been found down to 13.5 mag.

OMC camera experiment for INTEGRAL and search for Compton GRO BATSE LOCBURST optical transients

The test camera of the Optical Monitoring Camera (OMC) experiment for INTEGRAL spacecraft achieving an angular pixel size of 18 arcsec and a field of view 7.5°×5.1° has been successfully developed and tested at the Astronomical Institute Ondřejov. The test camera is able to provide imaging down to 15 mag over the whole field of view within one exposure of 300 seconds. Although developed primarily to test the OMC performance and help with software development, this device is ideally suited for use as a ground-based camera for sites where Compton Gamma Ray Observatory BATSE Locburst triggers are followed-up in the optical waveband and also for wide-field sky monitoring in general. The low cost of this camera makes it possible to duplicate the system at a number of observing sites. A chart and a corresponding CCD-image for the BACODINE Locburst Position 6368 taken with the OMC test camera at Ondřejov observatory are also presented. The image taken 18 hours after the trigger was computer-blinked with the fram...

The status of the Burst Observer and Optical Transient Exploring System (BOOTES)

The Burst Observer and Optical Transient Exploring System (BOOTES) is considered as a part of the preparations for the ESA’s satellite project INTEGRAL, and is currently being developed in Spain, in collaboration with two Czech institutions. It will make use of two sets of wide-field cameras 240 km apart, and two robotic 30 cm telescopes. All the instruments will be placed in Southern Spain. It is expected that BOOTES will provide rapid follow-up observations of GRBs detected by BATSE, BeppoSAX, RossiXTE and future experiments, as well as clarify whether optical transients, related or not to GRBs, are indeed of cosmic origin.