GCN Circular 5847
Subject
GRB 061121: MDM Optical Decay
Event
Date
2006-11-23T21:27:58Z (19 years ago)
From
Jules Halpern at Columbia U. <jules@astro.columbia.edu>
J. P. Halpern, N. Mirabal, & E. Armstrong (Columbia U.)
report on behalf of the MDM Observatory GRB follow-up team:
"We observed the afterglow GRB 061121 (Page et al., GCN 5823)
in the R band for a second night using the MDM 2.4m telescope.
The following magnitudes from fully reduced images supersede
and extend those reported by us in GCN 5840.
---------------------------------------------------------
Date(UT) Mid-time(UT) t-t0(hr) Exp(s) R(mag) +/-
---------------------------------------------------------
Nov. 22 11:57 20.57 300 21.10 0.03
Nov. 22 12:18 20.93 300 21.09 0.03
Nov. 22 12:26 21.06 300 21.10 0.03
Nov. 22 12:33 21.18 300 21.11 0.03
Nov. 22 12:41 21.32 300 21.15 0.03
Nov. 22 12:49 21.44 300 21.15 0.03
Nov. 23 11:46 44.39 300 22.08 0.08
Nov. 23 12:02 44.66 300 21.90 0.06
Nov. 23 12:08 44.76 300 21.92 0.06
Nov. 22 12:14 44.86 300 22.02 0.07
Nov. 23 12:20 44.96 300 21.98 0.07
Nov. 23 12:28 45.09 300 22.08 0.07
Nov. 23 12:36 45.23 300 21.99 0.07
Nov. 23 12:46 45.40 600 22.01 0.05
Nov. 23 12:57 45.58 600 22.13 0.07
---------------------------------------------------------
Magnitudes are referenced to a single USNO-B1.0 star at
(J2000) R.A.=09h48m54.77s, Decl.= -13d11'17.9" with R=18.02.
Quoted uncertainties are statistical only.
The power-law decay index from 21 to 45 hours is -1.08+/-0.03.
Images are posted at http://www.astro.columbia.edu/~jules/grb/061121/
This message may be cited."