{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"Research Square"}],"indexed":{"date-parts":[[2025,5,25]],"date-time":"2025-05-25T04:03:03Z","timestamp":1748145783777,"version":"3.41.0"},"posted":{"date-parts":[[2024,11,4]]},"group-title":"In Review","reference-count":0,"publisher":"Springer Science and Business Media LLC","license":[{"start":{"date-parts":[[2024,11,4]],"date-time":"2024-11-04T00:00:00Z","timestamp":1730678400000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2024,9,24]]},"abstract":"<title>Abstract<\/title>\n        <p>The interaction between convective motions and rotation in cool stars results in a dynamo process that drives magnetic surface activity1, 2. In single stars, activity increases with rotation rate until it saturates for stars with rotation periods Prot &lt; 3\u201310 d3, 4, 5. The mechanism responsible for saturation, however, remains unclear. Observations indicate that red giants in binary systems that are in spin-orbit resonance exhibit stronger chromospheric activity than single stars with similar rotation rates6, 7, 8, suggesting that tidal flows can influence surface activity. Here, we investigate the chromospheric activity of main-sequence binary stars to understand the impact of tidal forces on saturation phenomena. For binaries with 0.5 &lt; Prot\/d &lt; 1, mainly contact binaries sharing a common thermal envelope, we find enhanced activity rather than saturation. This result supports theoretical predictions that a large-scale \u03b1 \u2212 \u03c9 dynamo during common envelope evolution can generate strong magnetic fields9, 10, 11, 12. We also observe supersaturation in chromospheric activity, a phenomenon tentatively noted previously in coronal activity13, 4, where activity levels fall below saturation and decrease with shorter rotation periods. Our findings emphasise the importance of studying stellar activity in stars with extreme properties compared to the Sun\u2019s.<\/p>","DOI":"10.21203\/rs.3.rs-5147855\/v1","type":"posted-content","created":{"date-parts":[[2024,11,4]],"date-time":"2024-11-04T03:56:43Z","timestamp":1730692603000},"source":"Crossref","is-referenced-by-count":0,"title":["Enhanced magnetic activity in rapidly rotating binary stars"],"prefix":"10.21203","author":[{"given":"Jie","family":"Yu","sequence":"first","affiliation":[{"name":"The Australian National University"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0833-7084","authenticated-orcid":false,"given":"Charlotte","family":"Gehan","sequence":"additional","affiliation":[{"name":"Max Planck Institut f\u00fcr Sonnensystemforschung"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1463-726X","authenticated-orcid":false,"given":"Saskia","family":"Hekker","sequence":"additional","affiliation":[{"name":"Heidelberg Institute for Theoretical Studies"}]},{"given":"Mich\u00e4el","family":"Bazot","sequence":"additional","affiliation":[{"name":"Heidelberg Institute for Theoretical Studies"}]},{"given":"Robert","family":"Cameron","sequence":"additional","affiliation":[{"name":"Max-Planck-Institut fur SonnenSystemforscung"}]},{"given":"Patrick","family":"Gaulme","sequence":"additional","affiliation":[{"name":"Th\u00fcringer Landessternwarte"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5222-4661","authenticated-orcid":false,"given":"Timothy","family":"Bedding","sequence":"additional","affiliation":[{"name":"University of Sydney"}]},{"given":"Simon","family":"Murphy","sequence":"additional","affiliation":[{"name":"University of Southern Queensland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9204-7778","authenticated-orcid":false,"given":"Zhanwen","family":"Han","sequence":"additional","affiliation":[{"name":"Yunnan Observatory"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5082-9536","authenticated-orcid":false,"given":"Yuan-Sen","family":"Ting","sequence":"additional","affiliation":[{"name":"Australian National University"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4818-7885","authenticated-orcid":false,"given":"Jamie","family":"Tayar","sequence":"additional","affiliation":[{"name":"Uni-Florida"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5494-4339","authenticated-orcid":false,"given":"Yajie","family":"Chen","sequence":"additional","affiliation":[{"name":"Max-Planck Institute for Solar System Research"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7696-8665","authenticated-orcid":false,"given":"Laurent","family":"Gizon","sequence":"additional","affiliation":[{"name":"Max-Planck-Institut fuer Sonnensystemforschung"}]},{"given":"Jason","family":"Nordhaus","sequence":"additional","affiliation":[{"name":"RIT"}]},{"given":"Shaolan","family":"Bi","sequence":"additional","affiliation":[{"name":"Beijing Normal University"}]}],"member":"297","container-title":[],"original-title":[],"link":[{"URL":"https:\/\/www.researchsquare.com\/article\/rs-5147855\/v1","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.researchsquare.com\/article\/rs-5147855\/v1.html","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,5,24]],"date-time":"2025-05-24T07:07:53Z","timestamp":1748070473000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.researchsquare.com\/article\/rs-5147855\/v1"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,11,4]]},"references-count":0,"URL":"https:\/\/doi.org\/10.21203\/rs.3.rs-5147855\/v1","relation":{"is-preprint-of":[{"id-type":"doi","id":"10.1038\/s41550-025-02562-2","asserted-by":"subject"}]},"subject":[],"published":{"date-parts":[[2024,11,4]]},"subtype":"preprint"}}