[vsnet-grb-info 13577] GRB 130615A: Zadko observatory - Gingin optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14906
SUBJECT: GRB 130615A: Zadko observatory - Gingin optical observations
DATE:    13/06/15 22:02:27 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz at free.fr>

A. Klotz (IRAP-CNRS-OMP), D. Macpherson (UWA/ICRAR), D. Coward (UWA),
B. Gendre (IRAP-CNRS-OMP), M. Boer, K. Siellez, H. Dereli ,
O. Bardho (UNS-CNRS-OCA), A. Williams (PO-UWA), R. Martin (PO-UWA)
report:

We imaged the field of GRB 130615A detected by SWIFT
(trigger 558271) with the Zadko robotic telescope (D=100cm)
located at the observatory - Gingin, Australia.

The observations started 1.58h after the GRB trigger
just after the beginning of the night.
The elevation of the field increased from
30 degrees above horizon and weather conditions
were good.

We detect the afterglow candidate discovered
by Elliott et al. (GCNC 14898).

However, as mentioned by Frank et al. (GCNC 14901)
the stellar object stays at a constant magnitude
of R = 20.7 from 1.6h to 4.8h after the trigger.

Due to the absence of fading of its brightness,
we are not sure that the stellar object mentioned
by Elliott et al. (GCNC 14898) is the GRB afterglow.

Magnitudes were estimated with the nearby star
NOMAD-1 0218-0667138 (R.A.=274.8458361 Dec=-68.1621056
J2000) R=17.840. Magnitudes are not corrected for
galactic dust extinction.