Recent observations of peculiar Gamma-ray bursts using 3.6 m Devasthal Optical Telescope (DOT)

Abstract

India has been actively involved in the follow-up observations of optical afterglows of gamma-ray bursts (GRBs) for more than two decades, using the country's meter-class facilities such as the 1.04 m Sampurnanand Telescope, 1.3 m Devasthal Fast Optical Telescope, 2.01 m Himalayan Chandra Telescope along with many others in the country, utilizing the longitudinal advantage of the place. However, since 2016, Indian astronomers have embarked on a new era of exploration by utilizing the country's largest optical telescope, the 3.6 m Devasthal Optical Telescope (DOT) at the Devasthal Observatory of ARIES Nainital. This unique telescope has opened up exciting opportunities for transient study. Starting from the installation itself, the DOT has been actively performing the target of opportunity (ToO) observations, leading to many interesting discoveries. Notable achievements include the contributions towards the discovery of long GRB 211211A arising from a binary merger, the discovery of the most delayed optical flare from GRB 210204A along with the very faint optical afterglow (fainter than 25 mag in g-band) of GRB 200412B. We also successfully observed the optical counterpart of the very-high-energy (VHE) detected burst GRB 201015A using DOT. Additionally, DOT has been used for follow-up observations of dark and orphan afterglows, along with the observations of host galaxies associated with peculiar GRBs. More recently, DOT's near-IR follow-up capabilities helped us to detect the first near-IR counterpart (GRB 230409B) using an Indian telescope. In this work, we summarise the recent discoveries and observations of GRBs using the 3.6 m DOT, highlighting the significant contributions in revealing the mysteries of these cosmic transients.

16 pages, 2 figures, 1 table, accepted for publication in the Bulletin of Liège Royal Society of Sciences as a part of 3${}^{rd}$ Belgo-Indian Network for Astronomy and Astrophysics (BINA) workshop, 22-24 March 2023

References in corpus (9)

• A nearby long gamma-ray burst from a merger of compact objects
• Gamma Ray Bursts in the Swift-Fermi Era
• Phenomenology of Reverse-Shock Emission in the Optical Afterglows of Gamma Ray Bursts
• TANSPEC: TIFR-ARIES Near Infrared Spectrometer
• Revealing nature of GRB 210205A, ZTF21aaeyldq (AT2021any), and follow-up observations with the 4K$\times$4K CCD Imager+3.6m DOT
• The long-active afterglow of GRB 210204A: Detection of the most delayed flares in a Gamma-Ray Burst
• Prompt emission and early optical afterglow of VHE detected GRB 201015A and GRB 201216C: onset of the external forward shock
• Photometric studies on the host galaxies of gamma-ray bursts using 3.6m Devasthal Optical Telescope
• The closure relations in optical afterglow of Gamma-Ray Bursts

Cited by in corpus (1)

• A detailed time-resolved and energy-resolved spectro-polarimetric study of bright GRBs detected by AstroSat CZTI in its first year of operation