Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 21727

GRB 170823A: TAROT Calern observatory optical observations
2017-08-27T22:01:31Z (7 years ago)
Alain Klotz at IRAP-CNRS-OMP <>
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 170823A detected by SWIFT
(trigger 769177) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 28s after the GRB trigger
(18s after the notice). The elevation of the field decreased from
3 degrees above horizon and weather conditions
were very 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+28s to t0+88s : Rlim = 15.1

The second image is 30.0s exposure in tracking mode:
t0+101s to t0+131s : Rlim = 15.1

We co-added a series of exposures:
t0+101s to t0+395s : Rlim = 16.8

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.
Looking for U.S. government information and services? Visit