Abstract:
The 4 m International Liquid Mirror Telescope (ILMT) is a zenith-pointing optical observing facility at
ARIES Devasthal observatory (Uttarakhand, India). The ¯rst light preparatory activities of the ILMT
were accomplished in April 2022 followed by on-sky tests that were carried out at the beginning of May
2022. This telescope will perform a multi-band optical (SDSS g0
, r0 and i0
) imaging of a narrow strip ( 220
)
of sky utilizing the time-delayed integration technique. Single-scan ILMT images have an integration time
of 102 s and consecutive-night images can be co-added to further improve the signal-to-noise ratio. An
image subtraction technique will also be applied to the nightly recorded observations in order to detect
transients, objects exhibiting variations in °ux or position. Presently, the facility is in the commissioning
phase and regular operation will commence in March 2023. This paper presents a discussion of the main
preparation activities before ¯rst light, along with preliminary results obtained.
