TITLE:   GCN CIRCULAR
NUMBER:  14652
SUBJECT: GRB 130511A: SSO 2.3m observation
DATE:    13/05/15 02:34:36 GMT
FROM:    Fang Yuan at ANU  <yuanfang@mso.anu.edu.au>

F. Yuan, M. Childress, S. Rapoport, B. Schmidt, M. Dopita (Australian National University) and J. Scharwachter (Observatoire de Paris)

We observed the field of GRB 130511A (Krimm et al., GCN 14620) using the Wide Field Spectrograph (WiFeS) on the ANU 2.3m. Three 900s integration at resolution R=3000, covering 540 - 950nm, were obtained starting at 2013-05-11 12:03 UTC, ~32 minutes after the Swift trigger.

Spectral photometry of the sky-subtracted data cube was carried out in a 6" diameter aperture. Compared to a nearby field star, we measure the optical afterglow to be at r ~ 20.2 and i ~ 20.1 at a mean time of ~ 1 hr after the burst.
We thank Tiantian Yuan, Fred Vogt and Rebecca Davis for performing this observation.