[vsnet-grb-info 9179] GRB 100418A: ROVOR optical measurements at 35 hours

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10665
SUBJECT: GRB 100418A: ROVOR optical measurements at 35 hours
DATE:    10/04/23 23:41:42 GMT
FROM:    J. Ward Moody at BYU  <rovor.byu at gmail.com>

J. W. Moody, D. Laney, R. Pearson, and C. Pace report for the BYU ROVOR team:

Beginning approximately 35 hours after the initial detection of GRB 100418A we
obtained BVR optical data using the BYU WMO 0.9m telescope.
Preliminary magnitudes were found by referencing against USNO-B1.0
star 1014-0271368 (RA(J2000) = 17:05:26.42, Dec(J2000) = +11:27:32.9).
Assuming its values are B=18.66, R=17.32 (from catalog) and V=18.0
(our estimate) we obtain the following values:

post burst
t_mid(hr)   exp.(min)  filter  mag.  error
37.18        25            B      19.9  0.15
35.91        25            V      19.3  0.1
35.25        20            R      18.5  0.1


Poor weather has prevented subsequent observations.