Jelinek, M.; Kubanek, P.; Gorosabel, J.; Delgado, A. J.
GRB Coordinates Network, Circular Service, 10329, 1 (2010)
We observed the Swift-XRT errorbox of the GRB100115A (Margutti et al. GCN 10326) with the 2.56 Nordic Optical Telescope at La Palma. We acquired 7x 300s i' band exposure at about 32 hours after the GRB. The detection limit of this image is about i' = 24.0 mag.
We detect four sources within or at the border of the X-ray errorbox. None of these objects is present in the SDSS DR7 image, with the exception of A, which could be believed to be at the its very detection limit. This object also seems in our image extended and/or composed of two components.
Given the lack of astrometric information in the Updike et al. (GCN 10328) we cannot confirm or decide whether one of these objects is an optical afterglow of GRB100115A. We however do not see any object as bright as previously reported, which might confirm the decaying behaviour of the afterglow candidate by SARA.
The identification card with the objects marked A, B and C can be downloaded from http://www.iaa.es/mates/grb100115a-not-errorbox.jpg
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