The Telescope Bernard Lyot (TBL), with a primary mirror of 2 meters diameter, is located on the observation platform of the Pic du Midi de Bigorre, at an altitude of 2 877 meters atop the Pyrenees mountains. The TBL is managed by the Observatoire Midi-Pyrénées (OMP, France) / UAR831. It is a national telescope labeled « National Observing Service » INSU SNO3.
The TBL is operated in full service mode. It offers 350 clear hours in semester A (March to August) and 450 clear hours in semester B (September to February).
It now hosts the NeoNarval instrument, an Echelle spectro-polarimeter, stabilized in pressure and temperature since 2019 and which studies the stellar magnetism, the formation and evolution of stars and their planets.
It will host the SPIP instrument end of 2023.
The sectional view of the TBL locates the telescope inside the dome. At the Cassegrain focal plane of the telescope, the first module of the SPIP instrument, called Cassegrain module, performs the first light corrections and analyses.
The light beam is then transmitted to the lower stages through fibered links of 45 meters long.
The level “zero” receives the cryogenic spectrograph installed inside its dedicated isothermal chamber as well as the calibration and the control-command modules.
The Vision project, which consists in an opto-mechanical interface, is also planned to transmit the light to the 2 instruments, NeoNarval and SPIP, and thus allow simultaneous observations.
Sectional view of the Telescope Bernard Lyot
©Christophe Montheil
