Revised estimate of gravitational radiation from Crab and Vela pulsars

Abstract

PROGRESS in the development of ultra-high-Q dielectric crystals (Bagdasarov et al. unpublished data) has caused experimenters in the field of general relativity to look for rotation-induced gravitational radiation from pulsars (D. H. Douglass, unpublished data). If one could control the frequency of oscillation of a high-Q crystal, keeping it in phase with the electromagnetic signals observed from a pulsar, one might hope to absorb a measurable amount of (quadrupole) gravitational radiation at twice the pulsar frequency. Press and Thorne¹ in 1972 estimated that the gravitational waves from the Crab pulsar would produce a dimensionless strain in a detector on Earth of h∼10⁻²⁶ to 10⁻²⁸, and that other pulsars would be several orders of magnitude fainter. Additional observational data, and progress in pulsar models during the past five years, make a new estimate desirable. I report here that the amplitude of the gravitational waves from the Crab pulsar (PSR0531+21) is likely to be within 2 orders of magnitude of 10⁻²⁷, but that the Vela pulsar (PSR0833−45) is likely to produce waves of amplitude a factor 10 to 100 larger.