X-ray radiation detected inside the target galaxy NGC 3690 (NGC 3690-I1). This galaxy is not characterised by an active nucleus, so the radiation is likely generated by a number of X-ray emitters inside the galaxy. The time zero is set to MET = 411013065 s (2014-01-10). The fit performed on the data with a constant function returns a rate of 2.36 × 10^-2 counts s^-1, a χ² = 62.85 (35 d.o.f.) and p = 0.0026.