A Massive Pulsar in a Compact Relativistic Binary

TL;DR

This paper reports the discovery of a massive pulsar in a compact binary system, providing a crucial test of general relativity and insights into dense matter physics.

Contribution

It presents the measurement of a 2.01 solar mass pulsar in a tight orbit, offering new constraints on strong-field gravity and dense matter equations of state.

Findings

Orbital decay matches predictions of general relativity.

System constrains deviations from GR in strong gravity regimes.

Supports use of GR-based templates for gravitational wave detection.

Abstract

Many physically motivated extensions to general relativity (GR) predict significant deviations in the properties of spacetime surrounding massive neutron stars. We report the measurement of a 2.01 +/- 0.04 solar mass pulsar in a 2.46-hr orbit with a 0.172 +/- 0.003 solar mass white dwarf. The high pulsar mass and the compact orbit make this system a sensitive laboratory of a previously untested strong-field gravity regime. Thus far, the observed orbital decay agrees with GR, supporting its validity even for the extreme conditions present in the system. The resulting constraints on deviations support the use of GR-based templates for ground-based gravitational wave detectors. Additionally, the system strengthens recent constraints on the properties of dense matter and provides insight to binary stellar astrophysics and pulsar recycling.