Refined Mass and Geometric Measurements of the High-mass PSR J0740+6620

We report results from continued timing observations of PSR J0740+6620, a high-mass, 2.8 ms radio pulsar in orbit with likely ultracool white dwarf companion. Our data set consists combined pulse arrival-time measurements made the 100 m Green Bank Telescope and Canadian Hydrogen Intensity Mapping Experiment telescope. explore significance timing-based phenomena arising general relativistic dynamics variations dispersion. When using various statistical methods, we find that combining ∼1.5 yr additional, high-cadence previous confirms improves on estimates effects within J0740+6620 system, mass (68.3% credibility) determined by Shapiro time delay. For first time, measure secular variation orbital period argue this effect arises apparent acceleration due to significant transverse motion. After incorporating contributions Galactic differential rotation off-plane potential, obtain model-dependent distance kpc credibility). This improved nature companion recent optical observations. discuss prospects for future next-generation facilities, which will improve precision mp an order magnitude next few years.