{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/wide-twin-binaries-are-extremely-eccentric","title":"Wide twin binaries are extremely eccentric: evidence of twin binary formation in circumbinary disks","arxiv_id":"2205.05690","date":"2022-05-11","proceeding":null,"authors":["Hsiang-Chih Hwang","Kareem El-Badry","Hans-Walter Rix","Chris Hamilton","Yuan-Sen Ting","Nadia Zakamska"],"abstract":"The Gaia mission recently revealed an excess population of equal-mass \"twin\" wide binaries, with mass ratio $q\\gtrsim 0.95$, extending to separations of at least 1000 AU. The origin of this population is an enigma: twin binaries are thought to form via correlated accretion in circumbinary disks, but the typical observed protostellar disks have radii of $\\sim100$ AU, far smaller than the separations of the widest twins. Here, we infer the eccentricity distribution of wide twins from the distribution of their $v$-$r$ angles, i.e., the angle between the components' separation and relative velocity vectors. We find that wide twins must be on extremely eccentric orbits. For the excess-twin population at 400-1000 AU, we infer a near-delta function excess of high-eccentricity system, with eccentricity $0.95 \\lesssim e \\leq 1$. These high eccentricities for wide twins imply pericenter distances of order $10$ AU and suggest that their orbits were scattered via dynamical interactions in their birth environments, consistent with a scenario in which twins are born in circumbinary disks and subsequently widened. These results further establish twin wide binaries as a distinct population and imply that wide twins can be used as a probe of the dynamical history of stellar populations.","url_abs":"https://arxiv.org/abs/2205.05690v2","url_pdf":"https://arxiv.org/pdf/2205.05690v2.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"wide-twin-binaries-are-extremely-eccentric","repo_url":"https://github.com/hc-hwang/eccentricity-of-wide-binaries","is_official":0,"mentioned_in_paper":0,"mentioned_in_github":1,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}