{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"7eba8d5cc0eb03c436b0d6018973c8c0de52d4b15115c42b6e9537ea3155b62b","created":"2026-10-03T07:17:54Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"2acae7396954a21c683e6454d51fe199461d5ac7a859c79487467bc5bd7e03e2","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"astro.compact-binary-origins.common-envelope","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"Many merging pairs are thought to have shrunk when one star swelled and engulfed its companion, which spiraled in and blew off the shared envelope; whether the envelope can actually be thrown off and leave a tight enough orbit has not been shown.","posed_since":"1976","precise":"In common-envelope evolution the orbital energy released during inspiral must unbind the donor envelope, conventionally parametrized by $\\alpha_{\\mathrm{CE}}\\times\\lambda$. Determine from $3D$ hydrodynamics (with recombination energy, jets and post-plunge evolution) whether envelopes of $15\\ \\text{to}\\ 40\\ M_{\\mathrm{sun}}$ red supergiant donors are fully ejected, and whether final separations of a few $R_{\\mathrm{sun}}$, small enough to merge by gravitational waves within $1.4e10\\ \\mathrm{yr}$, result. Answer: final separation and ejected mass versus donor mass and radius, and the implied share of mergers from this route versus stable mass transfer.","problem_ref":null,"references":"","settled_by":"3D simulations followed to full envelope ejection or merger for massive donors, calibrated on observed post-common-envelope binaries.","status_note":"","title":"Can common-envelope ejection produce tight merging black-hole binaries?","topic_ref":"daba472bb0b714510fff4a7bb5a67935cfcb27a99af5cf911b7cdf92f4674c82"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"0a441ddb7c577e4fc1f88e4430a679e022128b3c40397b159fb3156aed7c2749","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"fda2a958d17c948751551aee8e78b32b126b66bfa46c492e8c4dd9991e1abc41","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"jYRtZsz1e1enezzuaQosLOrBxA1AATR66ekpGsctYdw-PltKW_-01ZyrsLcKFvL-NiRUC-lzNHr2TRJhICneCA"},"schema":"pubphys.envelope/1"},"record_hash":"0a441ddb7c577e4fc1f88e4430a679e022128b3c40397b159fb3156aed7c2749","leaf_index":495}