F. De Luise, F. Onori (INAF-OAAb), R. Carini, S Piranomonte (INAF-OAR), A.
Melandri (INAF-OAB), M. Canzari, M. Dolci, G. Valentini, A. Di Cianno, A.
Valentini, N. Napoleone, P. Tedesco (INAF-OAAb), E. Brocato (INAF-OAAb and
OAR) on behalf of the GRAWITA collaboration report:
On 2021-07-30 we observed the field of GRB210730A (Sonbas et al., GCN Circ.
30548; Prasad et al., GCN Circ. 30555; Wood et al., GCN Circ. 30577) with
the 0.9m Schmidt Telescope of the INAF - Astronomical Observatory of
Abruzzo located at 2150 meters a.s.l. at Campo Imperatore (Italy) and
equipped with a 4096x4096 CCD, covering a field of view of 1.15��1.15 square
A series of optical images of the field have been obtained with the r-Sloan
and z-Sloan filters on 2021-07-30. The observation started at 19:50:29 UT
(about 15 hr after the burst) for a total exposure time of 26x180s in r
band and 15x180s in z band, respectively.
A preliminary analysis does not show any optical counterpart candidate
within the XRT error circle (https://www.swift.ac.uk/xrt_positions/01062150/