{
  "bibcode": "2021GCN.29654....1K",
  "body": "H. Kumar (IITB), A. Dutta (IIA), R. Gupta (ARIES), V. Bhalerao (IITB), G.\nC. Anupama (IIA), S. Barway (IIA), D.K. Sahu (IIA),  A. Kumar (ARIES),\nDimple (ARIES), A. Ghosh (ARIES), S. B. Pandey (ARIES), and K. Misra\n(ARIES) report:\n\nWe observed GRB 210306A detected by Swift Burst Alert Telescope (V. D'Elia\net. al., GCN 29597) and optical afterglow confirmed by Alan M. Watson et.\nal., (GCN 29598) with the 2.0m Himalayan Chandra Telescope (HCT) of the\nIndian Astronomical Observatory. We obtained 6 exposures of 300 sec each in\nthe Bessell R filter. We did not detect the afterglow in our stacked image.\nThe photometric upper limit is:\n\n--------------------------------------------------------\n\n JD (mid) | T_mid-T0(hrs) | Filter | Lim_mag (5-sigma) |\n\n--------------------------------------------------------\n\n2459282.110905 | 58.76 | Bessell R | > 23.22 |\n\n--------------------------------------------------------\n\nThe magnitudes are in the AB system of magnitude calibrated against PanSTARRS\n(Flewelling et al., 2018) using Lupton's transformation equations available\nat http://classic.sdss.org/dr4/algorithms/sdssUBVRITransform.html#Lupton2005.\nThe magnitudes are not corrected for galactic extinction.\n\nThese observations were carried out under the ToO program HCT-2021-C1-P2.\nWe thank the HCT staff for their support during the observations. The\nIndian Astronomical Observatory is operated by the Indian Institute of\nAstrophysics, Bengaluru, India.",
  "circularId": 29654,
  "createdOn": 1615610674000,
  "email": "harshkosli13@gmail.com",
  "subject": "GRB 210306A: HCT optical upper limit",
  "submitter": "Harsh Kumar at Indian Inst of Tech,Bombay  <harshkosli13@gmail.com>",
  "eventId": "GRB 210306A"
}