We report the discovery of an eclipsing binary millisecond pulsar in the globular cluster M92 ( NGC6341 ) with the Five-hundred-meter Aperture Spherical radio Telescope ( FAST ) .
PSR J1717 + 4308A or M92A , has a pulse frequency of 316.5 Hz ( 3.16 ms ) and a dispersion measure of 35.45 pc cm ^ { -3 } .
The pulsar is a member of a binary system with an orbital period of 0.20 days around a low-mass companion which has a median mass of \sim 0.18 M _ { \odot } .
From observations so far , at least two eclipsing events have been observed in each orbit .
The longer one lasted for \sim 5000 s in the orbital phase range 0.1–0.5 .
The other lasted for \sim 500 s and occurred between 1000–2000 s before or after the longer eclipsing event .
The lengths of these two eclipsing events also change .
These properties suggest that J1717 + 4308A is a “ red-back ” system with a low-mass main sequence or sub-giant companion .
Timing observations of the pulsar and further searches of the data for additional pulsars are ongoing .