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GCN Circular 15921

GRB 140304A: NOT observations and redshift estimate
2014-03-04T21:44:36Z (10 years ago)
Antonio de Ugarte Postigo at IAA-CSIC <>
A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), J. Gorosabel (EHU-UPV,
IAA-CSIC), D. Xu (DARK/NBI), D. Malesani (DARK/NBI), A. Somero (NOT), 
B. Milvang-Jensen (DARK/NBI), M.I. Andersen (DARK/NBI), P. Jakobsson 
(U. Iceland) and J.P.U. Fynbo (DARK/NBI) report on behalf of a larger collaboration:

We have observed the afterglow of 140304A (Gorbovskoy et al. GCN 15914, Evans et 
al. GCN 15915) with the Nordic Optical Telescope (NOT) equipped with ALFOSC. 
Observations started at 20:19 UT on March 4 (i.e., 6.95 hr after the burst) in r and g-bands.
The afterglow is clearly detected in r-band at 20.5 mag, but undetected in g-band down to 
a 3-sigma limit of 21.5, pointing towards a high-redshift event at z ~ 5 if the Lyman break 
is between g and r-band. 

Further observations are ongoing.
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