Recent ART-XC observations of Sgr A* on August 15-16 (2019-08-14T23:40 – 2019-08-15T14:00 and 2019-08-15T23:40 – 2019-08-16T14:00, UTC) with total exposure of 50 ks each, demonstrate source average 5-16 keV flux at the level of 1.6×10-11 erg cm-2 s-1, which corresponds to the luminosity of 1.4×1035 erg s-1 , assuming a distance of 8.5 kpc. This measurement of the source luminosity is comparable to that observed with ART-XC on August 12 (ATel #13023). We also see a small flux variability at the level of 15% on the timescale of a few hours. More detailed information will be provided in the corresponding publication, which is under preparation.
Multi-wavelength observations are encouraged; next time when ART-XC will observe Sgr A* is between 2019-08-22T05:46 and 2019-08-22T15:20 UTC.