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The Télescope Bernard Lyot


Built on the Pic du Midi de Bigorre, the 2-m TBL produces night-time data for French and European professional astronomers, with instruments at the cutting edge of high-resolution spectropolarimetry. It stands out as an internationally pioneering site for research on stellar magnetism and the birth and life of stars and their planets. Its staff comprises 15 experts in electronics, electrotechnics, optomechanics, cryogenics, embarked systems and astronomical observation. Operated in full-service mode, it complies with thorough quality control at all the stages of the observation process.

Built in 1980 at an altitude of 2,877 m (9,438 ft), this telescope is the main sky sentinel in France with its 2 m-diameter primary mirror. Originally used for research in all astrophysics fields, its vocation shifted when NARVAL was built in 2006, making it the first observatory in the world dedicated to the study of stellar magnetism.

Why study the magnetic field of stars?


An essential ingredient in the life of stars, magnetic fields are both witnesses to their history and driving forces in their evolution. For instance, the magnetic field of the Sun might have caused the so-called "Little Ice Age" which reached its peak in Europe from the 16th to the 19th century. Magnetic fields are even likely to perturb the birth of stars by changing the amount of matter they emerge from. Yet, little is known about them: even the Solar magnetic field remains a mystery! A mystery which might be solved through observing the magnetic fields of other stars, just as a physician examines a number of patients to unveil the secrets of an illness.

First major results

The magnetic field of a star is akin to a common magnet, however its north and south poles reverse on a regular basis (about every 11 years in the case of the Sun). For the first time, an astrophysics research team has "caught" another star (Tau Boötis A) performing its "magnetic switch".

Tau Boötis A seems to switch poles more frequently than the Sun. Is this due to the presence of its close-orbiting giant planet? This discovery has given researchers a better understanding of how magnetic cycles function in stars like the Sun.

NARVAL was designed and built by the research teams as the Toulouse/Tarbes astrophysics laboratory, with funding from Région Midi-Pyrénées, the Ministry of Research, the European Union, Conseil général Hautes-Pyrénées and CNRS.


Localisation : Pic du Midi de Bigorre (La Mongie)

Structure de rattachement : Observatoire Midi Pyrénées

Responsable : CABANAC Rémi

Adresse : OMP, 57 ave d'Azereix, 65000 TARBES

Tél/@ : 0562566042;

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