From Super-Eddington to zero: following a Z source into quiescence

XTE J1701462 is probably the most luminous Galactic transient neutron star LMXB(NSXB) in the history of Xray astronomy. Early observations have alreadyclarified our view on the role of mass accretion rate in NSXBs. Observing XTEJ1701462 as it returns to quiescence will create a unique opportunity to studythe effects of massaccretion rate on the spectral/variability properties in asingle NSXB over an unprecedented luminosity range. We propose a Chandra/XMMNewton TOO program with two goals: 1) observe the source during the end ofthe decay and in quiescence, to complete what might well become a .Rosettastone. for NSXBs and 2) constrain the structure of neutron stars by studying theeffects of nearEddington accretion on the cooling of the crust/core in transient NSXBs. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]