GCN Circular 20289

Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP),
Boer, M., Laugier, R. (CNRS-ARTEMIS),
Gendre B. (UVI - Etelman Obs.) report:

We imaged the field of GRB 161217A detected by SWIFT
(trigger 727167) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 133.3s after the GRB trigger
(18.3s after the notice). The elevation of the field increased from
65 degrees above horizon and weather conditions
were good.

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT with a limiting magnitude of:
t0+133.3s to t0+193.3s : Rlim = 16.3

The second image is 30.0s exposure in tracking mode:
t0+208.6s to t0+238.6s : Rlim = 16.9

We co-added a series of exposures:
t0+208.6s to t0+611.7s : Rlim = 18.1

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.