GCN Circular 14673

A. Melandri (INAF-OAB), V. D'Elia (ASDC), P. D'Avanzo (INAF-OAB), M.  
Della Valle (INAF-OAC), E. Pian (INAF-OAT/SNS), G. Tagliaferri (INAF- 
OAB) on behalf of a larger collaboration report:

We have observed the field of GRB 130427A (Maselli et al., GCN 14448
Not found
 
 
)  
for 9 epochs from t-t0=6.7 to t-t0=18.8 days after the burst event.   
The preliminary light curve in BVR and I bands does not show any  
evidence of a bump related to a SN, and it is marginally consistent  
with a SN component, which should be at least 2 mag fainter than 98bw  
at maximum.

The spectrum (2x1800s) of 13 May, after comparison with SN2010bh  
template, is suggestive, in the range 5000A-7500A of broad GRB-SN  
features, but altogether, we don't find the good similarity that the  
GTC finds (de Ugarte-Postigo et al., CBET 3529). The spectrum of the  
transient (after subtraction of a galaxy template) is available at:

http://www.brera.inaf.it/utenti/davanzo/grb/GRB130427A/GRB130427A.png

Observations have been taken in the framework of the ESO-Program  
091.D-0291 (PI E. Pian).