Bulletin de la Société Royale des Sciences de Liège Bulletin de la Société Royale des Sciences de Liège -  Volume 93 - Année 2024  No 2 - Proceeedings of the 3rd BINA Workshop on the Scientific Potential of the Indo-Belgian Cooperation 

Necessity of a TDI Optical Corrector for ILMT Observations

Vibhore Negi
Aryabhatta Research Institute of Observational sciencES (ARIES), Manora Peak, Nainital, 263001, India and Department of Physics, Deen Dayal Upadhyaya Gorakhpur University, Gorakhpur, 273009, India. Corresponding author: vibhore.negi18@gmail.com
Bhavya Ailawadhi
Aryabhatta Research Institute of Observational sciencES (ARIES), Manora Peak, Nainital, 263001, India and Department of Physics, Deen Dayal Upadhyaya Gorakhpur University, Gorakhpur, 273009, India
Talat Akhunov
National University of Uzbekistan, Department of Astronomy and Astrophysics, 100174 Tashkent, Uzbekistan and Ulugh Beg Astronomical Institute of the Uzbek Academy of Sciences, Astronomicheskaya 33, 100052 Tashkent, Uzbekistan
Ermanno Borra
Department of Physics, Université Laval, 2325, rue de l’Université, Québec, G1V 0A6, Canada
Monalisa Dubey
Aryabhatta Research Institute of Observational sciencES (ARIES), Manora Peak, Nainital, 263001, India and Department of Applied Physics, Mahatma Jyotiba Phule Rohilkhand University, Bareilly, 243006, India
Naveen Dukiya
Aryabhatta Research Institute of Observational sciencES (ARIES), Manora Peak, Nainital, 263001, India and Department of Applied Physics, Mahatma Jyotiba Phule Rohilkhand University, Bareilly, 243006, India.
Jiuyang Fu
Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
Baldeep Grewal
Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
Paul Hickson
Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
Brajesh Kumar
Aryabhatta Research Institute of Observational sciencES (ARIES), Manora Peak, Nainital, 263001, India
Kuntal Misra
Aryabhatta Research Institute of Observational sciencES (ARIES), Manora Peak, Nainital, 263001, India
Kumar Pranshu
Aryabhatta Research Institute of Observational sciencES (ARIES), Manora Peak, Nainital, 263001, India and Department of Applied Optics and Photonics, University of Calcutta, Kolkata, 700106, India
Ethen Sun
Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
Jean Surdej
Institute of Astrophysics and Geophysics, University of Liège, Allée du 6 Août 19c, 4000 Liège, Belgium

Abstract

The International Liquid Mirror Telescope (ILMT) has recently become operational at the Devasthal Observatory of ARIES, Nainital, India. The ILMT observes in the Time delay integration (TDI) mode where the images are formed by electronically stepping the charges over the pixels of the CCD, along a column. Observations near the zenith impose certain constraints dependent on the latitude such as image deformation due to the star-trail curvature and differential speed. These effects make the stellar trajectories in the focal plane of the ILMT to be hyperbolic, which are corrected for by the introduction of a TDI optical corrector, designed specifically for the ILMT. Here, we report the first results on the effect of this corrector on the trajectories followed by the stars in the ILMT focal plane. Astrometrically calibrating nine nights of data recorded with the ILMT during its first commissioning phase, we find simple (nearly linear) relations between the CCD-y coordinate and the right ascension (RA) of stars and between the CCD-x coordinate and their declination (DEC), respectively, which confirms that the TDI corrector works very fine in converting the stellar trajectories into straight lines.

Keywords : Liquid mirror telescope, survey, TDI optical corrector, astrometry

Pour citer cet article

Vibhore Negi, Bhavya Ailawadhi, Talat Akhunov, Ermanno Borra, Monalisa Dubey, Naveen Dukiya, Jiuyang Fu, Baldeep Grewal, Paul Hickson, Brajesh Kumar, Kuntal Misra, Kumar Pranshu, Ethen Sun & Jean Surdej, «Necessity of a TDI Optical Corrector for ILMT Observations», Bulletin de la Société Royale des Sciences de Liège [En ligne], Volume 93 - Année 2024, No 2 - Proceeedings of the 3rd BINA Workshop on the Scientific Potential of the Indo-Belgian Cooperation, 863-871 URL : https://popups.uliege.be/0037-9565/index.php?id=11904.