{
  "bibcode": "2004GCN..2594....1M",
  "body": "GRB 040511: Second Epoch Optical Observations\n\nNidia Morrell (Las Campanas Observatory), Hsiao-Wen Chen (MIT), Joshua S.\nBloom (Harvard/CfA), Jason X. Prochaska (UCO/Lick), A. Dullighan, G.\nRicker, N. Butler, and R. Vanderspek (MIT):\n\n\"We have obtained a second epoch of R-band images of the field around GRB\n040511 (Dullinghan et al., GCN #2588) using the SITe#3 CCD imager on the\n40 inch Swope telescope at the Las Campanas Observatory.  The observations\nwere carried out starting at 01:30 UT 13 May 2004 (~36 hours after the\nburst).  Three exposures of 600 sec duration were taken under photometric\nand sub-arcsec seeing conditions.  The 5-sigma depth of the stacked image\nis R~23.6 mag over a 2\"-diameter aperture.\n\nA comparison of the stacked image with the first-epoch images obtained at\n~11 hr after the burst (Chen et al., GCN #2591) shows that none of the\n~7100 sources of Rc <~ 23 in the 14.8' x 20' region have variability by\nmore than 0.25 mag. The few larger-amplitude outliers in the magnitude\n(epoch1) vs. magnitude (epoch2) plot are due to detector artifacts.\"\n\nThe magnitude-magnitude plot that shows the comparison of object\nphotometry obtained from two epochs and all the imaging data are publicly\navailable at http://www.graasp.org/. Click the \"Data\" link.\n\nThis message may be cited.",
  "circularId": 2594,
  "createdOn": 1084429849000,
  "email": "jbloom@cfa.harvard.edu",
  "subject": "GRB 040511: Second Epoch Optical Observations",
  "submitter": "Josh Bloom at Harvard/CFA  <jbloom@cfa.harvard.edu>",
  "eventId": "GRB 040511"
}