[vsnet-grb-info 13415] GRB 130603B: Gemini Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14748
SUBJECT: GRB 130603B: Gemini Observations
DATE:    13/06/04 03:11:31 GMT
FROM:    Antonino Cucchiara at UCSC/UCO Lick  <acucchia at ucolick.org>

A. Cucchiara (UCSC/UCO Lick), D. Perley (Caltech), and
S. B. Cenko (GSFC) report on behalf of a larger collaboration:

On June 3.97 UT we start observing the optical afterglow 
of the Short GRB 130603B (Melandri et al. GCN 14735,
Evans et al., GCN 14739, Levan et al. GCN 14742, and 
de Ugarte Postigo et al. GCN 14743) with the Gemini-South
telescope equipped with the GMOS camera.
The observation sequence consists of a series of 8x3min
exposures in the g',r' and i' filters.

The OT is clearly detected in individual exposures.  
Using the coadded frames and a 0.7" aperture, 
we estimate the following magnitudes:

g = 21.7 +/- 0.2
r = 21.2 +/- 0.1
i = 20.7 +/- 0.2

These are not corrected for Galactic extinction or for 
contribution of the host galaxy, which is likely significant.
An RGB image of the field showing the optical transient has been 
posted to:
http://www.astro.caltech.edu/~dperley/gcn/130603b/130603b_gmos.png

Also, a spectroscopic sequence was obtained: based on CaHK lines and 
several emission lines we confirm the redshift of GRB 130603B to be
z=0.356 (as also reported by Thoene et al. GCN. 14744, Foley 
et al. 14745).

We thank the Gemini South Staff, in particular A. Cardwell, J. Turner
and Mischa Schirmer, for the excellent support.