Abstract:

Pulsars in tight binaries can be weighed dynamically, but accurate mass estimates are often hampered by uncertainties in orbital inclinations. In this talk, I present a new finding from a multi-epoch optical monitoring of the pulsar binary, PSR J1048+2339. Our observations reveal frequent optical flares with eclipses caused by the companion. Using the eclipse duration with archival photometric data and orbital ephemeris in the literature, we constrain the inclination to 78+/-1 degrees and the pulsar mass to 1.79 (+0.09, −0.08) solar masses. This measurement is among the most precise for any redback system to date, demonstrating a novel way to improve the pulsar mass measures with small aperture optical telescopes.