Hulse–Taylor binary pulsar

Hulse–Taylor binary pulsar
Name	PSR B1913+16
Discovery date	1974
Discoverer	Russell Hulse, Joseph Taylor Jr.
Constellation	Aquila
Primary	Neutron star
Companion	Neutron star
Period	7.75 hours

Hulse–Taylor binary pulsar is a binary system in Aquila comprising two compact objects, discovered in 1974 by Russell Hulse and Joseph Taylor Jr.. The system provided the first indirect evidence for gravitational waves through the measurement of orbital decay, influencing research at institutions such as Princeton University, Massachusetts Institute of Technology, Stanford University, and observatories like the Arecibo Observatory. The discovery led to the 1993 Nobel Prize in Physics awarded to Hulse and Taylor and shaped missions including LIGO, VIRGO, and planning for LISA.

Discovery and observational history

The pulsar was detected during radio surveys conducted at the Arecibo Observatory by a team including Russell Hulse and Joseph Taylor Jr., using techniques developed earlier at Naval Research Laboratory, Harvard–Smithsonian Center for Astrophysics, and Cornell University. Early timing analyses employed software and methodologies from groups at Bell Labs and Caltech and built on timing frameworks used for objects like PSR B0329+54 and PSR B1937+21. Follow-up observations were made with facilities such as the Green Bank Telescope, Jodrell Bank Observatory, and Parkes Observatory, with long-term campaigns coordinated with teams at National Radio Astronomy Observatory and Max Planck Institute for Radio Astronomy. Observational history includes studies published in journals like Astrophysical Journal, Nature, and Physical Review Letters, and collaborations with researchers affiliated with University of Manchester, University of Bonn, and Columbia University.

System properties and orbital parameters

The system consists of a radio-emitting neutron star in orbit with a compact companion identified as a neutron star, with component masses inferred using relativistic timing parameters in the framework of Kepler's laws extended by general relativity. Measured parameters include an orbital period of about 7.75 hours and an eccentricity near 0.617; the projected semi-major axis and periastron advance were determined using timing models similar to those applied to binary pulsars such as PSR J0737−3039A/B. Periastron precession, gravitational redshift, and Shapiro delay were quantified using analysis tools from groups at University of California, Berkeley and University of Amsterdam. Mass estimates around 1.4 solar masses per component align with equations of state studied at Los Alamos National Laboratory, Oak Ridge National Laboratory, and theoretical work by researchers at Princeton University and Cambridge University.

Tests of general relativity and gravitational radiation

Timing measurements produced a secular decrease in orbital period matching the prediction of gravitational radiation reaction from general relativity, providing indirect confirmation of Einstein’s theory as formulated in The Meaning of Relativity era discussions and later theoretical refinements by groups at Institute for Advanced Study and Kip Thorne’s collaborators at Caltech. Results were compared to post-Newtonian calculations developed in institutions such as University of Maryland, Copenhagen University, and University of Chicago. The precision of the orbital decay measurement informed sensitivity targets for detectors like LIGO Scientific Collaboration, VIRGO, and GEO600, and motivated data-analysis pipelines at CERN and Max Planck Institute for Gravitational Physics. Constraints from the system also influenced alternative-gravity tests considered at Stanford University and University of Cambridge.

Evolution and fate of the binary

Stellar-evolution models attribute the system’s origin to massive binary progenitors undergoing supernovae, mass transfer episodes, and common-envelope phases modeled by groups at University of Tokyo, Monash University, and University of Birmingham. Binary population synthesis performed by teams at University of Sussex and Northwestern University predicts eventual inspiral and coalescence due to continued orbital energy loss from gravitational-wave emission, culminating in a merger analogous to events cataloged by LIGO/Virgo Collaboration such as GW170817. The merger outcome could form a heavier neutron star or a black hole, with nucleosynthetic and electromagnetic counterparts akin to kilonovae studied by researchers at University of Warwick and European Southern Observatory. Long-term evolution also considers effects modeled in research at University of California, Santa Cruz and Instituto de Astrofísica de Canarias.

Impact on astrophysics and Nobel Prize

The discovery reshaped observational and theoretical astrophysics, spurring advances at institutions like Massachusetts Institute of Technology, Harvard University, and Caltech in pulsar timing arrays, gravitational-wave astronomy, and nuclear physics of dense matter. The 1993 Nobel Prize in Physics recognized Hulse and Taylor for the discovery, impacting funding and programs at organizations including National Science Foundation, European Research Council, and national observatories. The system influenced subsequent surveys by teams at Square Kilometre Array planning groups, motivated proposals within National Aeronautics and Space Administration, and informed curriculum and outreach at universities such as University of Cambridge and Imperial College London.

Observational techniques and instrumentation

Detection and monitoring relied on radio-pulsar timing techniques developed using instrumentation at the Arecibo Observatory, Green Bank Telescope, and Parkes Observatory, employing backend processors and correlators from suppliers associated with National Radio Astronomy Observatory and firmware designs tested at Jodrell Bank Observatory. Precision timing required clock standards traceable to International Bureau of Weights and Measures references and time-transfer systems used by Jet Propulsion Laboratory and European Space Agency. Data analysis utilized pulsar timing packages originating from collaborations at University of Manchester and Princeton University, and motivated upgrades in interferometric arrays at Very Large Array and projects at Square Kilometre Array Organisation.

Category:Binary pulsars Category:Neutron stars