[vsnet-grb-info 18480] GRB 160917A: OSN I-band upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19928
SUBJECT: GRB 160917A: OSN I-band upper limits
DATE:    16/09/17 20:49:18 GMT
FROM:    Zach Cano at U of Iceland  <zewcano at gmail.com>

A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), Z. Cano (IAA-CSIC) & F. Aceituno
(IAA-CSIC) report on behalf of a larger collaboration:

We observed the field of GRB 160917A (Racusin et al.; GCN Circ. 19926) with
the 1.5-m OSN telescope in Granada, Spain.  We began observing at 19:08:34
UT (7.64 hours after the GRB onset), and obtained 14x300s images in
I-band.  In our coadded image, we find no new source in the refined XRT
error circle (Evans et al; GCN Circ. 19927) down to a a 3-sigma limit of
I(Vega) = 22.6.  The calibration was performed using a nearby star in the
USNO B1 catalog, and the upper limit corresponds to an isolated point
source in our co-added image.