Gravitational waves from spinning neutron stars as not-quite-standard sirens

Understand

As is well known, gravitational wave detections of coalescing binaries are standard sirens, allowing a measurement of source distance by gravitational wave means alone.

• In this paper we explore the analogue of this capability for continuous gravitational wave emission from individual spinning neutron stars, whose spin-down is driven purely by gravitational wave emission.
• We show that in this case, the distance measurement is always degenerate with one other parameter, which can be taken to be the moment of inertia of the star.
• We quantify the accuracy to which such degenerate measurements can be made.