{"paper":{"title":"Temporal evolution and correlations of optical activity indicators measured in Sun-as-a-star observations","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.SR","authors_text":"A. Collier Cameron, A. F. Lanza, A. Ghedina, A. Mortier, A. Sozzetti, C.-H. Li, C. Watson, D. F. Phillips, D. Sasselov, E. Molinari, E. Poretti, F. Pepe, G. Micela, G. Piotto, H. M. Cegla, J. Costes, J. Guerra, J. Maldonado, J. San Juan, K. Rice, L. Malavolta, M. Cecconi, M. Gonzalez, M. Lodi, N. Hern\\'andez, R. Cosentino, R. D. Haywood, S. H. Saar, S. Thompson, S. Udry, T. Milbourne, X. Dumusque","submitted_at":"2019-06-07T10:45:57Z","abstract_excerpt":"(Abridged) We perform a detailed study of the main optical activity indicators (Ca II H & K, Balmer lines, Na I D$_{\\rm 1}$ D$_{\\rm 2}$, and He I D$_{\\rm 3}$) measured for the Sun using the data provided by the HARPS-N solar-telescope feed at the Telescopio Nazionale Galileo. The value of the solar rotation period is found in all the activity indicators, with the only exception being H$\\delta$. The derived values vary from 26.29 days (H$\\gamma$ line) to 31.23 days (He I). From an analysis of sliding periodograms we find that in most of the activity indicators the spectral power is split into s"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1906.03002","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}