PSR J0514 - 4002A is a 5-ms pulsar is located in the globular cluster NGC 1851 ; 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 \dot { \omega } = 0.01289 ( 4 ) ^ { \circ } yr ^ { -1 } , which if due completely to general relativity , implies a total system mass of 2.453 ( 14 ) M _ { \odot } ; we also derive m _ { p } < 1.5 M _ { \odot } and m _ { c } > 0.96 M _ { \odot } .
The companion is likely to be a massive white dwarf star .