{
  "bibcode": "2022GCN.31711....1K",
  "body": "S. Klose, A. Nicuesa Guelbenzu, B. Stecklum, S. Melnikov, F. Ludwig (all \nTLS Tautenburg) report:\n\nWe observed the field of the Swift/Fermi GRB 220306B (Caputo et al., GCN \n31697; Wood et al., GCN 31782) with the Tautenburg 1.34m Schmidt telescope \nequipped with the TAUKAM 6kx6k CCD camera. Observations were performed on \nMarch 8, 2022, between 00:03 and 00:34 UT, about 30 hours after the burst.\n\nInside the enhanced XRT error circle (Evans et al., GCN 31700) we do not \ndetect any source. Close to the error circle we detect two sources.\n\nSource 1 lies at RA, DEC (J2000) = 00:21:33.42, +71:21:46.7 (+/- 0.5 \narcsec) and is located at the south-eastern border of the XRT error \ncircle. For this source we measure the following AB magnitudes:\n\nr = 21.33 +/- 0.16,\ni = 20.67 +/- 0.10,\nz = 20.28 +/- 0.16,\n\ncalibrated against the Pan-STARRS catalog.\n\nThis source was already detected and discussed by Belkin et al. (GCN \n31705). Our r-band data confirm that it is fading and that light from an \nunderlying permanent object starts to dominate.\n\nSource 2 lies at at RA, DEC (J2000) = 00:21:33.52, +71:21:51.9 and is \nlocated at the north-eastern border of the enhanced XRT error circle. For \nthis source we measure r > 22.2 (3 sigma), i = 21.27 +/- 0.17, z = 20.83 \n+/- 0.25. The nature of this source is uncertain; obviously it is \nunrelated to the GRB.",
  "circularId": 31711,
  "createdOn": 1646760924000,
  "email": "klose@tls-tautenburg.de",
  "subject": "GRB 220306B: Tautenburg observations",
  "submitter": "Sylvio Klose at TLS Tautenburg  <klose@tls-tautenburg.de>",
  "eventId": "GRB 220306B"
}