{
  "bibcode": "2009GCN..9234....1S",
  "body": "P.Schady (MSSL/UCL) and J. K. Cannizzo (NASA/UMBC) report on behalf of the \nSwift/UVOT team:\n\nThe Swift/UVOT started settled observations of the burst GRB090424 \n(Cannizzo et al. GCN Circ. 9223) with the finding chart (fc) exposure in \nwhite, 167s after the BAT trigger. The afterglow is detected in the all \nfilters at the position reported by Cannizzo et al. (GCN Circ. 9223), \nplacing an upper limit on the redshift of ~1.3.  The combined UVOT data \nindicates that the afterglow is fading with a decay index of alpha ~ 0.9.\n\nThe UVOT magnitudes our reported below:\n\nFilter    Tmid(s)   Exp(s)   Magnitude\nwhite (fc) 167        147.4   15.27 +/- 0.01\nu (fc)     429        245.8   16.40 +/- 0.03\n\nwhite      594        19.4    16.99 +/- 0.07\nv          644        19.5    16.86 +/- 0.19\nb          570        19.5    17.27 +/- 0.13\nu          1122       19.5    17.44 +/- 0.20\nuvw1       695        19.5    16.81 +/- 0.19\nuvm2       670        19.4    17.39 +/- 0.34\nuvw2       793        19.4    17.51 +/- 0.27\n\nThe values quoted above are in the UVOT photometric system (Poole et al. \n2008, MNRAS, 383, 627) and are not corrected for the expected Galactic \nextinction corresponding to a reddening of E(B-V)=0.025 mag in the \ndirection of the burst (Schlegel et al. 1998).",
  "circularId": 9234,
  "createdOn": 1240609357000,
  "email": "sro@mssl.ucl.ac.uk",
  "subject": "Swift/UVOT observations of GRB 090424",
  "submitter": "Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>",
  "eventId": "GRB 090424"
}