The eccentric binary millisecond pulsar in NGC 1851

PSR J0514-4002A is a 5-ms pulsar is located in the globular cluster NGC 185 1; it belongs to a highly eccentric (e = 0.888) binary system. It is one of the earliest known examples of a numerous and fast-growing class of eccentric binary MSPs recently discovered in globular clusters. Using the GBT, we have obtained a phase-coherent timing solution for the pulsar, which includes a measurement of the rate of advance of periastron (omega) over dot = 0.01289(4)degrees yr(-1), which if due completely to general relativity, implies a total system mass of 2.453(14)M-circle dot; we also derive m(p) 1.5M(circle dot) and m(c) 0.96M(circle dot). The companion is likely to be a massive white dwarf star.