The 4m International Liquid Mirror Telescope

The International Liquid Mirror Telescope (ILMT) consists of a 4-m diameter zenith telescope with a liquid mirror characterized by a f/2 focal ratio. It is a collaborative project between Belgium, Canada, India and Poland. The participating institutions are: Institute of Astrophysics and Geophysics of the Liege University (IAGL), the Royal Observatory of Belgium (ROB), six Canadian universities (British Columbia, Laval, Montreal, Toronto, Victoria and York), the Aryabatta Research Institute of Observational Sciences (ARIES, Nainital, India) and the Observatory of Poznan (UAM, Poland). This telescope is being installed at the Devasthal observatory, India (Longitude 79° 41' 04'' E, +29° 21' 40'' N, altitude 2450m), in the central Himalayas. First light should happen in early 2016. It will image every night a strip of sky having an approximate width of 27' in declination using a 4096 x 4096 pixel CCD detector that will work in the time delay integration (TDI) mode. The ILMT will thus perform a deep survey of a long and narrow strip of sky by looking at stars, galaxies, AGN, quasars, asteroids, space debris, ... crossing its field of view. It will observe in the i', r', g' SDSS spectral bands. This survey will thus be mainly dedicated to photometric and astrometric variability studies of faint objects. Among the main scientific goals, let us mention the detection and follow up of a few tens of multiply imaged quasars produced by gravitational lensing, hundreds of supernovae every year, detection of nearby brown dwarfs, white dwarfs and other faint stars based upon their trigonometric parallax and/or proper motion measurements, photometric variability studies of thousands of quasars and millions of stars as well as space debris detection at dusk and/or at dawn. Right now, numerous data sets have already been obtained of the ILMT strip of sky with smaller telescopes in the TDI mode. These will be used to carry out preliminary scientific projects and calibration of the ILMT data. A pipeline and database are presently in construction at the Poznan Observatory. Some videos and recent photographs will illustrate the present status of the ILMT project.