{"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/x-ray-activity-on-the-star-planet-interaction","title":"X-ray Activity Variations and Coronal Abundances of the Star-Planet Interaction candidate HD 179949","arxiv_id":"2211.01011","date":"2022-11-02","proceeding":null,"authors":["Anshuman Acharya","Vinay L. Kashyap","Steven H. Saar","Kulinder Pal Singh","Manfred Cuntz"],"abstract":"We carry out detailed spectral and timing analyses of the $Chandra$ X-ray data of HD 179949, a prototypical example of a star with a close-in giant planet with possible star-planet interaction (SPI) effects. We find a low coronal abundance $A({\\rm Fe})/A({\\rm H}){\\approx}0.2$ relative to the solar photospheric baseline of Anders & Grevesse (1989), and significantly lower than the stellar photosphere as well. We further find low abundances of high First Ionization Potential (FIP) elements $A({\\rm O})/A({\\rm Fe}){\\lesssim}1$, $A({\\rm Ne})/A({\\rm Fe}){\\lesssim}0.1$, but with indications of higher abundances of $A({\\rm N})/A({\\rm Fe}){\\gg}1, A({\\rm Al})/A({\\rm Fe}){\\lesssim}10$. We estimate a FIP bias for this star in the range $\\approx{-0.3}$ to ${-0.1}$, larger than the ${\\lesssim}-$0.5 expected for stars of this type, but similar to stars hosting close-in hot Jupiters. We detect significant intensity variability over time scales ranging from 100 s - 10 ks, and also evidence for spectral variability over time scales of 1-10 ks. We combine the $Chandra$ flux measurements with $Swift$ and XMM-$Newton$ measurements to detect periodicities and determine that the dominant signal is tied to the stellar polar rotational period, consistent with expectations that the corona is rotational-pole dominated. We also find evidence for periodicity at both the planetary orbital frequency and at its beat frequency with the stellar polar rotational period, suggesting the presence of a magnetic connection between the planet and the stellar pole. If these periodicities represent an SPI signal, it is likely driven by a quasi-continuous form of heating (e.g., magnetic field stretching) rather than sporadic, hot, impulsive flare-like reconnections.","url_abs":"https://arxiv.org/abs/2211.01011v3","url_pdf":"https://arxiv.org/pdf/2211.01011v3.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":"x-ray-activity-on-the-star-planet-interaction","repo_url":"https://github.com/anshuman1998/csresid","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}