TITLE:   GCN CIRCULAR
NUMBER:  7501
SUBJECT: GRB 080319B: optical upper limit
DATE:    08/03/21 18:51:16 GMT
FROM:    Giuseppe Greco at U Bologna  <giuseppe.greco2@studio.unibo.it>

G. Greco (Bologna University), F. Terra (Second University of
Roma "Tor Vergata"), C. Bartolini, A. Guarnieri, A. Piccioni
(Bologna University), F. Munz, G. Pizzichini (INAF/IASF Bologna),
D. Nanni (INAF/OAR and Second University of Rome "Tor Vergata"),
A. Shearer (Centre for Astronomy, Galway), R. Gualandi 
(Bologna Observatory) report:

We observed the field of GRB 080319B (GCN 7427, Racusin et al.)  
with the 152 cm telescope located in Loiano under unfavorable
conditions due to the illumination of the full moon. 

By adding four consecutive 10 min exposures in the Rc filter at 
mean time 2008 March 20.947 UT we do not detect any object at
the position of the optical bright afterglow reported by 
Racusin et al. (GCN 7428).

Our 3-sigma limiting magnitude is R~20.3 (based on Nomad1 catalogue).

The image has been posted in our public directory 
from where it can be retrieved 
by sftp using 
hostname: ermione.bo.astro.it
username: publicGRB
password: GRB_bo.
directory: GRB080319B