{"paper":{"title":"Star-planet magnetic interactions in photoevaporating exoplanets: enhanced power due to atmospheric escape","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Higher planetary escape rates open extra magnetic flux and raise star-planet interaction power as the square root of the normalized mass-loss rate.","cross_cats":[],"primary_cat":"astro-ph.EP","authors_text":"Aline A. Vidotto, Andr\\'es Presa, Filip Elekes","submitted_at":"2026-04-07T16:46:34Z","abstract_excerpt":"Observations of periodic stellar activity near the transit phase of a close-in exoplanet provide evidence of star-planet magnetic interactions (SPMI), similar to the magnetic coupling between Jupiter and its moons. Comparing the power associated with SPMI signals to analytical theories offers a way to constrain exoplanetary magnetic fields, but models based on moon-magnetosphere analogs often underpredict observed energy fluxes. Unlike moons, many close-in exoplanets are extended, highly irradiated gas giants undergoing significant photoevaporation. However, it is not known how atmospheric esc"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"For higher escape rates, the planetary outflow opens additional magnetic flux, and the SPMI power increases proportionally with (Md / M0)^{1/2}. Applying this scaling law to the HD18973 system, we find that a 30 G planet could reproduce the observed power if Md ~ 10^{12} g/s.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The 3D radiation MHD simulations correctly capture the dominant physics of magnetic flux opening by the planetary outflow without significant numerical artifacts, missing non-ideal effects, or unmodeled time-dependent stellar wind variations; the threshold M0 is accurately defined solely by pressure balance.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Simulations of photoevaporating hot Jupiters show that star-planet magnetic interaction power follows the Alfvén wing model below a critical mass-loss rate and scales as the square root of the normalized mass-loss rate above it.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Higher planetary escape rates open extra magnetic flux and raise star-planet interaction power as the square root of the normalized mass-loss rate.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"36fedab4d010810e5b4f18f27e021863a636abdf68680c90aa861a1f8560aee2"},"source":{"id":"2604.06064","kind":"arxiv","version":2},"verdict":{"id":"3ee40302-00b3-4bcf-b2bc-189098f2f2b4","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-10T18:37:41.241618Z","strongest_claim":"For higher escape rates, the planetary outflow opens additional magnetic flux, and the SPMI power increases proportionally with (Md / M0)^{1/2}. Applying this scaling law to the HD18973 system, we find that a 30 G planet could reproduce the observed power if Md ~ 10^{12} g/s.","one_line_summary":"Simulations of photoevaporating hot Jupiters show that star-planet magnetic interaction power follows the Alfvén wing model below a critical mass-loss rate and scales as the square root of the normalized mass-loss rate above it.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The 3D radiation MHD simulations correctly capture the dominant physics of magnetic flux opening by the planetary outflow without significant numerical artifacts, missing non-ideal effects, or unmodeled time-dependent stellar wind variations; the threshold M0 is accurately defined solely by pressure balance.","pith_extraction_headline":"Higher planetary escape rates open extra magnetic flux and raise star-planet interaction power as the square root of the normalized mass-loss rate."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2604.06064/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":2,"snapshot_sha256":"4bac656161f3b0151b24a7982be0201dcda7cf53a8058f082521a604806b107d"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}