In this paper we review recent discovery of millisecond pulsars ( MSPs ) in eccentric binary systems .
Timing these MSPs we were able to estimate ( and in one case precisely measure ) their masses .
These results suggest that , as a class , MSPs have a much wider range of masses ( 1.3 to > 2 M _ { \odot } ) than the normal and mildly recycled pulsars found in double neutron star ( DNS ) systems ( 1.25 < M _ { p } < 1.44 M _ { \odot } ) .
This is very likely to be due to the prolonged accretion episode that is thought to be required to form a MSP .
The likely existence of massive MSPs makes them a powerful probe for understanding the behavior of matter at densities larger than that of the atomic nucleus ; in particular , the precise measurement of the mass of PSR J1903+0327 ( 1.67 \pm 0.01 M _ { \odot } ) excludes several ” soft ” equations of state for dense matter .