Abstract We concentrate on several items of long-term activity of soft X-ray transients (SXTs). The existence of known neutron star (NS) SXTs is not dependent on the orbital period P_{orb}, which indicates a large scatter of the mass transfer rate in low-mass X-ray binaries of a given P_{orb}. We investigate the role of irradiation of the disk on several examples of SXTs and show the cases when it evolves during outburst. We interpret the variations of the recurrence time T_{C} of outbursts of Aql X-1 and 4U 1608-52; the outbursts are triggered near the optically thin ADAF region and propagate outward in the disk. The outer disk region is brought to the hot state only in the rare, most intense outbursts. The amount of mass accreted largely varies for the individual outbursts in a given SXT. We also argue that the change of T_{C} in the Rapid Burster is caused by an increase of the disk viscosity. The cyclic modulation of T_{C} of GRS 1747-312 can suggest stellar activity of the donor. We interpret the so-called echo outbursts in KS 1731-260 as a series of outside-in outbursts, dependent on each other.

Keywords Stars: neutron accretion accretion disks binaries: close circumstellar matter X-rays: binaries

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