TAROT

Télescopes à Action Rapide pour les Objets Transitoires

This page gives useful informations about the TAROT observatories and their scientific programs.

For an image gallery click here.

1. Description of TAROT observatories

1.1. Current status

TAROT are robotic observatories that observe with no human interaction. TAROT are two identical 25 cm telescopes F/D=3.4 that cover 1.86°x1.86° field of view on the Andor CCD cameras (Marconi 4240 back illuminated). Spatial sampling is 3.3 arcsec/pix. Six filters are available : BVRI, a clear filter and a 2.7 density coupled to V (for Moon and planets). Detection limit is about V=17 in 1 min. exposure. Locations of telescopes are:
The princpal investigator of these intruments is Michel Boër (Observatoire de Haute Provence, 04870 Saint Michel l'Observatoire, France). Two co-investigators are Jean-Luc Atteia and Alain Klotz, astronomers at the Observatoire Midi Pyrénées, Toulouse, France. We have collaborations with Yassine Damerdji, Myrtille Laas-Bourez, Christian Pollas, Raoul Berhend, Alessandra Corsi, Alessandra Galli, Eric Frappa, Bruce Gendre, Jean-François Leborgne, Frédéric Malacrino, Luigi Piro, Giullia Stratta.

Calern

Calern

Calern

La Silla

La Silla

La Silla

Observation requests are send by observers through an internet interface or by the Gamma-ray Coordinates Network (GCN) through a socket. Planning is computed each time a new request is received. Telescope slewing is very fast, up to 60°/second, and read-out time of CCD cameras is only 5 seconds. When a GCN alert is received, the delay until the opnening of the shutter is less than 8 seconds.

Raw images are automatically processed by TCL scripts runned by AudeLA software to provide reduced data ready use for researcher collaborators via web pages

TAROT are not only used for gamma ray bursts observations. They are also used by collaborators concerning many other scientifi projects (see Section 2), as well as educational programs.

Each observatory has a reliability higher than 90% and produce about 80 000 images per year. An project of Vitural Observatory archive should be achieved before end of 2008.

1.2. History of TAROT

2. Scientific programs with TAROT

All publications can be read in this page.

2.1. Gamma-Ray Bursts

The main goal of TAROT is to be always ready to react to a GCN alert. GCN alerts are provided by satellites devoted to GRB detection at high energies. In optical wavelengths, we distinguish the prompt phase, when the GRB is still active in gamma rays, and the afterglow phase, corresponding to the late emissions. TAROT is specialized to the prompt phase observations in optical wavelengths. Two main results came from TAROT:

2.2. Discovery of new variable stars

Each TAROT image is measured by the Sextractor software that extract all sources. These sources are gathered in a huge database where variable stars are automatically recognized. Many hundred of such new variable stars are found (TSVSC1 catalog).

2.2. The RR Lyrae stars

Amongst pulsating stars, RR Lyrae are known to have variations of their periods. TAROT is used to determine the date of maxima of brightness of these stars. Variations of periods of few dozen of stars have been discovered and characterized by TAROT.

2.3. Minor planets

TAROT is used to confirm binary asteroids that exhibit eclipses. Moreover, TAROT monitor the stars predicted to be occulted by asteroids. This program allows to determine diameters and shapes of minor planets.


Negative occultation by Photographica at around 2003-12-25T20:37:58.080


Positive occultation by Wallia at around 2004-04-23T23:24:56

2.4. Supernovae

Each image taken by TAROT is croped to extract sub-images centered of known nearby galaxies (z<0.03). Then, sub-images are visually controled to find new supernovae.

Supernova 2004et prediscovered by TAROT

3. About Gamma-Ray Bursts

3.1. Some milestones

3.2. Some usefull links

3.3. Glossary