Telescope Bernard Lyot (TBL), the 2.03 m National telescope located at the Pic du Midi Observatory, is a Palomar-type equatorial telescope and is completely computer remote controlled from out of the dome.
It is equipped with NARVAL, a cross-dispersed echelle spectrograph/spectropolarimeter fed by an optical fiber link from a Cassegrain module containing all calibration facilities and an optional polarisation analyser, making it possible to have very good wavelength stability and minimal instrumental polarisation. NARVAL gives a complete optical spectrum (370 to 1000 nm) in a single exposure with a resolving power of about 65 000, and all polarisation components of the stellar light (circular and linear) with the same resolving power.
A description of the instrument performances can be found in Aurière 2003 (http://cdsads.u-strasbg.fr/abs/2003EAS…..9..105A)
All observations are done in service observing mode.
Observing time is allocated by the French Time Allocation Committee twice a year, for semesters A (from March 1st to August 31st; deadline: mid-October) and semesters B (from September 1st to February 28th; deadline: mid-April), for proposals with a French P.I., or through the OPTICON call (https://www.astro-opticon.org/). Otherwise, observing time can be purchased at any time (contact: eric.josselin@obs-mip.fr).
In the course of Semester 2019B, a new spectropolarimeter will be installed: Neo-Narval is a stabilized (< 3 m/s) spectropolarimeter, covering the same domain as NARVAL, with a similar spectral resolution.
An exposure time calculator for NARVAL is available at:
http://www.ast.obs-mip.fr/users/donati/calculator_narval/etcform_nar.html
At this stage, it is assumed that it also applies to Neo-Narval.
We point out that a near-infrared spectropolarimeter is planned for 2022. SPIP (« SpectroPolarimètre Infrarouge au Pic du midi ») will be a copy of SPIRou, mounted at CFHT, covering the domain 0.98-2.35 μm at a spectral resolution of 75 000. A description of SPIRou is given by Donati et al. 2018 (http://cdsads.u-strasbg.fr/abs/2018haex.bookE.107D).