{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"4dcdf1d973eb5ae7c3e08e621e7273a2621590ea46063bf8e4b50594f797137c","created":"2026-10-03T07:17:55Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"24c176fc689739c9d2f690a48681e6cdde4bfbee2f93f6f12f20c7b2f662d4d3","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"astro.radius-valley.neptune-desert","kind":"phenomenon","literature_status":"open","n":"1","parents":[],"plain":"Planets the size and mass of Neptune are rare on orbits shorter than a few days, even though both smaller and larger planets are found there. Starlight stripping their gas, and the way giant planets arrive in such close orbits, are proposed causes.","posed_since":"","precise":"Neptune-mass and Neptune-radius planets are depleted at $P$ below $\\sim 2-4\\,\\mathrm{d}$, with the upper desert boundary following mass decreasing with period and a differently shaped lower boundary (Mazeh, Holczer and Faigler 2016, A&A 589, A75). Determine whether photoevaporation of irradiated sub-Neptunes sets the lower boundary and the tidal-disruption limit of high-eccentricity migration sets the upper one (Owen and Lai 2018, arXiv:1807.00012), or whether formation-location or tidal decay effects dominate. The answer is a mechanism reproducing both boundaries versus stellar type and age.","problem_ref":null,"references":"","settled_by":"Masses, radii, ages and measured escape rates (helium $10830\\,\\mathrm{Angstrom}$ and Lyman-alpha transits) for planets in and near the desert from TESS follow-up, compared with each boundary's predicted dependence on host properties.","status_note":"","title":"What empties the hot Neptune desert?","topic_ref":"29eecacca9d688759063e837d47b7481ed1a91ff74dcb512159e65510cf6039a"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"5c0406e02bf3762a49ab4f9ab874d9296ca23952397cedaa49b23cb45f30b3d4","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"f4ed54f79060c145112f3ec512fc874c81157c3030f27c6210a7f6680bdde46c","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"lqlqd3y-P0U6E5u5WvHihskp1m4bmsfkjE8i4kEQQ4R-n-HmWqqAOiYaq7fKAWopEE-tSjMzDDRVDTrxB33cCg"},"schema":"pubphys.envelope/1"},"record_hash":"5c0406e02bf3762a49ab4f9ab874d9296ca23952397cedaa49b23cb45f30b3d4","leaf_index":595}