Robuta

https://test.gcn.nasa.gov/circulars/30695 GCN - Circulars - 30695 - GRB 210820A: GROND observations gcn circulars grb grond observations https://gcn.nasa.gov/circulars/30668 GCN - Circulars - 30668 - GRB 210820A: Swift-XRT refined Analysis gcn circulars grb swift xrt