HETE J1900.1-2455 is returning to quiescence
The most recently-discovered millisecond pulsar, HETE J1900.1-2455, has finally begun to fade into quiescence. The last couple of observations in May saw the flux below 10-10 erg cm-2 s-1, and fading, as reported in ATel #1086. Collaborators in the Netherlands, led by Rudy Wijnands, triggered a series of Swift observations, which confirmed the decline. Swift observations are ongoing, and a Chandra pointing is planned for the end of June. HETE J1900.1-2455 was active for almost 2 years — longer by far than any of the other accretion-powered millisecond pulsars. We're sorry to see it go!
Flux history (.PS) from RXTE