{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"fb5a483c0d7ce5b3d60a1eb6853200cacfaf6da2dab2f5fbdad77dca47ae4446","created":"2026-10-03T07:17:55Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"d9c89656d1e949c475288999ad4cb756a3be4c97195d97fc4900c582204777d8","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"astro.neutron-star-interiors.cw-mountains","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"A spinning neutron star with a tiny bump on its crust would emit a steady gravitational-wave hum. None has been detected, and it is not known how large a bump the crust can support or how large real bumps are.","posed_since":"","precise":"Searches for continuous gravitational waves from known pulsars set upper limits on ellipticity $\\epsilon$ of order $1e-8\\ \\text{to}\\ 1e-9$ for some nearby millisecond pulsars. Determine the maximum ellipticity a realistic crust can sustain (estimates range from about $1e-9\\ \\text{to}\\ 1e-6$ depending on how the mountain is built) and whether a floor near $\\epsilon \\sim 1e-9$ exists, as suggested by millisecond-pulsar spin-down.","problem_ref":null,"references":"","settled_by":"A detection of continuous gravitational waves, or a crust-elasticity calculation with a self-consistent formation history giving $\\epsilon_{\\mathrm{max}}$ below current limits.","status_note":"Searches of LIGO-Virgo-KAGRA fourth observing run data were in progress in 2026 with no reported detection.","title":"How large are neutron-star mountains, given no continuous gravitational waves?","topic_ref":"afd1feb0d7ec84994296c83f9c2ecba96e22fc9ddf5d5fa7c0562e1f6f4eb1d4"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"6b685a71d394ce7d9d2643fbf7d1920ba56f4c584eb8b55669d69377a2e88983","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"3c9d68d074712ea02b101cf52ae535bc3e56ec9303313699f16c5828dbe4a368","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"4uvYcQADbZc4qlrLeou89DSocM-jANHbKyc2f4gbnPNiL6ceJ-80LY8jyFngmH12F3eN_AZ3_nNGK4N2T8HkBg"},"schema":"pubphys.envelope/1"},"record_hash":"6b685a71d394ce7d9d2643fbf7d1920ba56f4c584eb8b55669d69377a2e88983","leaf_index":572}