[AAVSO-HEN] GRB 070517: Gemini optical imaging

[grb at aavso.org]

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TITLE:   GCN CIRCULAR
NUMBER:  6420
SUBJECT: GRB 070517: Gemini optical imaging
DATE:    07/05/19 04:44:01 GMT
FROM:    Derek Fox at PSU  <dfox at astro.psu.edu>

D.B. Fox (Penn State), P.A. Price (Hawaii), and E. Berger (Carnegie
Observatories) report:

"We observed the refined XRT localization (Vergani & Romano, GCN 6414)
of GRB 070517 (Vergani et al., GCN 6411) with the Gemini South
telescope + GMOS-S, in a series of exposures beginning 03:23 UT on May
18, 2007.

Within the refined XRT localization we identify a point-like source at
coordinates R.A. 18:30:29.12, Dec -62:17:50.7 (uncertainty of <0.75"
in each coordinate).  This source is not present in DSS images of the
region, although at an estimated brightness of r'=22.1 mag, i'=22.0
mag it lies beyond the depth of that survey.  The source is detected
in all of our imaged filters, g', r', i', and z'.

We also identify a possible point-like source at coordinates
R.A. 18:30:29.07, Dec -62:17:52.3 (uncertainty of <1.0" in each
coordinate).  This source is detected in the i' and z' bands only,
with brightness i'~24.5 mag.

Further observations will be necessary to assess the variable /
afterglow nature of these sources."