{
  "bibcode": "2011GCN.11516....1K",
  "body": "N.P.M. Kuin (MSSL/UCL) and J.M. Gelbord (PSU) report on behalf of\nthe Swift/UVOT team:\n\nAs reported earlier (Gelbord et al., GCN Circ. 11473; Kuin et al.,\nGCN Circ. 11482), Swift/UVOT observations of GRB 101219B detected an\noptical afterglow in all its bands with initial magnitudes of about\n18 mag. The optical afterglow has been unusually slow to decay, and\nis around 23 mag at present in the u and uv bands. The UVOT has\nobtained a good light curve in all bands up to about 300ks, with\ncontinuing detections through 1000ks in u, uvw1, uvm2, and uvw2 (v\nand b measurements after 300ks are significantly affected by the PSF\nwings of a B = 15.5 mag star located 7 arcsec to the SW). The light\ncurve still appears to be decaying and there is some indication that\nthis decay may not be smooth.\n\nGRB 101219B is further interesting because the UVOT light curve\nexhibits an early decay to about 600 seconds after the trigger time\nT, after which a second brightness rise to a maximum around T+850s\noccurs. A corresponding break is found in the X-ray light curve, in\nthat the decay observed by XRT flattens approximately at T+700s.\n\nThe only constraint on the redshift of this burst is an upper limit\naround 1.5 implied by the detection in uvw2, as there have not been\nany spectroscopic observations announced to date. However, if this\nburst is bright because it is close, then we might detect a supernova\nbump in the coming days.\n\nWe consider this an interesting burst and would like to bring this\nto the attention of the community as an opportunity for further\nobservations.",
  "circularId": 11516,
  "createdOn": 1294097489000,
  "email": "jgelbord@astro.psu.edu",
  "subject": "GRB 101219B: After 2 weeks still detected by Swift/UVOT",
  "submitter": "Jonathan Gelbord at PSU/Swift  <jgelbord@astro.psu.edu>",
  "eventId": "GRB 101219B"
}