TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4810
SUBJECT: GRB 060218: rebrightening
DATE:    06/02/22 03:48:28 GMT
FROM:    Daniele Malesani at SISSA-ISAS,Trieste,Italy  <malesani@sissa.it>

P. D'Avanzo (INAF/OABr), D. Malesani (SISSA/ISAS), M. Della Valle 
(INAF/OAA), D. Fugazza (INAF/OABr), N. Masetti, E. Palazzi (INAF/IASF 
Bo), E. Pian (INAF/OATs), L.A. Antonelli, V. D'Elia, F. Fiore, S. 
Piranomonte, L. Stella (INAF/OAR), S. Campana, G. Chincarini, S. Covino, 
G. Tagliaferri (INAF/OABr), L. Di Fabrizio (INAF/TNG), report:

We observed again the optical counterpart of GRB 060218 (Moretti et al. 
GCN 4775; Marshall et al., GCN 4779) with the TNG telescope. Comparison 
between our previous photometry (taken on Feb 20.85 UT) and the new 
observations (Feb 21.84 UT) reveals a rebrightening by 0.20+-0.05 mag in 
both the V and R filters.

Following the earlier decay (e.g. Marshall et al., GCN 4800; Berger et 
al., GCN 4808), this behaviour may mark the emergence of the underlying 
SN 2006aj already suggested on spectroscopic grounds (Masetti et al., 
GCN 4803; Soderberg et al., IAUC 8674; Fugazza et al., GCN 4807, CBET 
410; Mirabal et al., CBET 409; Fatkhullin et al., GCN 4809). The 
rebrightening may also suggest that the SN is still before its maximum.

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