The puzzling temporally variable optical and X-ray afterglow of GRB 101024A
B. Gendre1, G. Stratta1, M. Laas-Bourez2, D. M. Coward3, A. Klotz4,5, S. Cutini1, M. Boër5 and C. Stockdale6
1 ASI Science Data Center, via Galileo Galilei, 00044 Frascati (RM), Italy
2 University of Western Australia, School of Physics/ICRAR, W.A. 6009 Crawley, Australia
3 University of Western Australia, School of Physics, W.A. 6009 Crawley, Australia
4 Institut de Recherche en Astrophysique et Planetologie, 9 avenue du colonel Roche, 31028 Toulouse, France
5 Observatoire de Haute Provence (CNRS), 04780 Saint Michel l’Observatoire, France
6 Centre for Backyard Astrophysics, 3842 Churchill Victoria, Australia
Received: 27 February 2011
Accepted: 11 April 2011
Aims. We present the optical observations of the afterglow of the Swift burst GRB 101024A and try to reconcile these observations with the X-ray afterglow data of GRB 101024A using current afterglow models
Methods. We employ early optical observations, using the Zadko Telescope combined with X-ray data, to compare them with the reverse shock/forward shock model.
Results. The early optical light curve reveals a very unusual steep decay index of α ~ 5. This is followed by a flattening and possibly a plateau phase coincident with a similar feature in the X-ray. We discuss these observations in the framework of the standard reverse shock/forward shock model and energy injection. The plateau phase might also be the signature of the formation of a new magnetar.
Key words: gamma-ray burst: general
© ESO, 2011