Born in 1971 in Moscow, Denisenko graduated from Moscow Institute of Physics and Technology (MIPT or Phystech) in 1993 with a Master of Science in Astrophysics and a Diploma: Spectral Properties of Gamma-Ray Bursts Observed by PHEBUS Instrument of the Granat observatory.
He has been an amateur astronomer since 1977, a member of the Moscow Astronomy Club since 2002 and the head of a working group on asteroidal occultations.