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GCN Circular 6343

GRB 070411: break in the optical light curve
2007-04-23T15:09:04Z (17 years ago)
Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center <>
D. Malesani (DARK/NBI), E. Rol (Univ. Leicester), L. A. Antonelli
(INAF/OAR), J.P.U. Fynbo (DARK/NBI), P.A. Curran (UVA), K. Wiersema (UVA),
A.J. Levan (Univ. Warwick), N.R. Tanvir (Univ. Leicester), V. Testa
(INAF/OAR), E. Palazzi (INAF/IASF Bo), A.O. Jaunsen (Univ. Oslo), C.C.
Thoene (DARK/NBI), J. Hjorth (DARK/NBI), P.M. Vreeswijk (ESO), report:

We have observed the optical afterglow of GRB 070411 (Moretti et al., GCN
6267), using the NOT, VLT, TNG, and WHT telescopes, in the R band.

Observations were carried out at several epochs, between 0.04 and 8 days
after the burst. Analysis of the light curve reveals a clear steepening at
~1 day after the GRB. The late-time slope alpha ~ 1.4 is well constrained
by our measurements (see also Ferrero et al., GCN 6319), and has a value
flatter than expected from post-jet break models (alpha >~ 2).

We encourage observations at X-ray wavelengths to test for the presence of
any break in the X-ray light curve.

We acknowledge support from the observers and the staff at the NOT, VLT,
TNG, and WHT telescopes.
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