[vsnet-grb-info 23449] GRB 190828B: optical upper limit from 0.5m Savelli Robotic Telescope

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  25548
SUBJECT: GRB 190828B: optical upper limit from 0.5m Savelli Robotic Telescope
DATE:    19/08/29 14:35:27 GMT
FROM:    Andrea Melandri at INAF-OAB  <andrea.melandri at brera.inaf.it>

A. Brosio (Oss. Astr. Savelli), A. Melandri (INAF-OAB), E. Palazzi (INAF-OAS), L. Nicastro (INAF-OAS), M.A. Tripodi (Oss. Astr. Savelli), S. Savaglio (UniCal) on behalf of a larger collaboration report:


We observed the field of GRB 190828B (Dichiara et al., GCN 25517) with the 0.5m Savelli Robotic Telescope (SRT) located at the Osservatorio Astronomico Lilio (Savelli, Italy). The observations were performed starting on 2019 August 28 at 19:19:22 UT (i.e. about 6.3 hours after the burst) and consisted of 24x300s exposures in the r-sdss band. 

No optical counterpart is detected nearby the XRT enhanced position (Beardmore et al., GCN 25521) in our stacked image, down to a 5sigma limiting magnitude of r>20.5, at a mean time of about 7.48 hours after the GRB. Calibration was performed against the SDSS catalog.