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We report on continued monitoring observations of the Galactic center carriedout by the X-ray telescope aboard the Swift satellite in 2008 and 2009. Thiscampaign revealed activity of the five known X-ray transients AX J1745.6-2901,CXOGC J174535.5-290124, GRS 1741-2853, XMM J174457-2850.3 and CXOGCJ174538.0-290022. All these sources are known to undergo very faint X-rayoutbursts with 2-10 keV peak luminosities of Lx,peak~1E34-1E36 erg/s, althoughthe two confirmed neutron star low-mass X-ray binaries AX J1745.6-2901 and GRS1741-2853 can also become brighter (Lx,peak~1E36-1E37 erg/s). We discuss theobserved long-term lightcurves and X-ray spectra of these five enigmatictransients. In 2008, AX J1745.6-2901 returned to quiescence following anunusually long accretion outburst of more than 1.5 years. GRS 1741-2853 wasactive in 2009 and displayed the brightest outburst ever recorded for thissource, reaching up to a 2-10 keV luminosity of Lx~1E37 (D/7.2 kpc)^2 erg/s.This system appears to undergo recurrent accretion outbursts approximatelyevery 2 years. Furthermore, we find that the unclassified transient XMMJ174457-2850.3 becomes bright only during short episodes (days) and is oftenfound active in between quiescence (Lx~1E32 erg/s) and its maximum outburstluminosity of Lx~1E36 erg/s. CXOGC J174535.5-290124 and CXOGC J174538.0-290022,as well as three other very-faint X-ray transients that were detected by Swiftmonitoring observations in 2006, have very low time-averaged mass-accretionrates of ~< 2E-12 Msun/yr. Despite having obtained two years of new data in2008 and 2009, no new X-ray transients were detected.

A four-year baseline Swift study of enigmatic X-ray transients located near the Galactic center