We propose a scenario for a periodic filling and emptying of the accretion disc of GRS 1915+105 , by computing the mass transfer rate from the donor and comparing it with the observed accretion rate ( see the full paper [ 3 ] ) .
The binary parameters found by [ 1 ] predict evolutionary expansion of the donor along the giant branch with a conservative mass transfer rate ( 1 – 2 ) \times 10 ^ { -8 } M _ { \odot } yr ^ { -1 } .
This reservoir can support the present observed accretion rate with a duty cycle 0.05 – 0.1 ( the active time as a fraction of the total life time ) .
The viscosity time scale at the circularization radius ( 15 solar radii from the primary 14 M _ { \odot } black hole ) is identified as the recurrent quiescent time during which a new disc is formed once consumed by the BH .
For small viscosity ( \alpha = 0.001 ) it equals to 300 – 400 years .
The microquasar phase , with the duty cycle , will last around 10 ^ { 7 } years ending with a long-period black hole + white dwarf system .