{"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/discovery-and-validation-of-a-high-density","title":"Discovery and Validation of a High-Density sub-Neptune from the K2 Mission","arxiv_id":"1601.07608","date":"2016-01-28","proceeding":null,"authors":["Néstor Espinoza","Rafael Brahm","Andrés Jordán","James S. Jenkins","Felipe Rojas","Paula Jofré","Thomas Mädler","Markus Rabus","Julio Chanamé","Blake Pantoja","Maritza G. Soto","Katie M. Morzinski","Jared R. Males","Kimberly Ward-Duong","Laird M. Close"],"abstract":"We report the discovery of BD+20594b, a high density sub-Neptune exoplanet, made using photometry from Campaign 4 of the two-wheeled Kepler (K2) mission, ground-based radial velocity follow-up from HARPS and high resolution lucky and adaptive optics imaging obtained using AstraLux and MagAO, respectively. The host star is a bright ($V=11.04$, $K_s = 9.37$), slightly metal poor ([Fe/H]$=-0.15\\pm 0.05$ dex) solar analogue located at $152.1^{+9.7}_{-7.4}$ pc from Earth, for which we find a radius of $R_*=0.928^{+0.055}_{-0.040}R_\\odot$ and a mass of $M_* = 0.961^{+0.032}_{-0.029}M_\\odot$. A joint analysis of the K2 photometry and HARPS radial velocities reveal that the planet is in a $\\approx 42$ day orbit around its host star, has a radius of $2.23^{+0.14}_{-0.11}R_\\oplus$, and a mass of $16.3^{+6.0}_{-6.1}M_\\oplus$. Although the data at hand puts the planet in the region of the mass-radius diagram where we could expect planets with a pure rock (i.e. magnesium silicate) composition using two-layer models (i.e., between rock/iron and rock/ice compositions), we discuss more realistic three-layer composition models which can explain the high density of the discovered exoplanet. The fact that the planet lies in the boundary between \"possibly rocky\" and \"non-rocky\" exoplanets, makes it an interesting planet for future RV follow-up.","url_abs":"http://arxiv.org/abs/1601.07608v2","url_pdf":"http://arxiv.org/pdf/1601.07608v2.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":"discovery-and-validation-of-a-high-density","repo_url":"https://github.com/nespinoza/exonailer","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":1,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"syntology_url":null,"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}