Examinando por Autor "Sarkis, Paula"

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    A New Sample of Warm Extreme Debris Disks from the ALLWISE Catalog
    (Institute of Physics, 2021-03-20) Moór, Attila; Ábrahám, Péter; Szabó, Gyula; Vida, Krisztián; Cataldi, Gianni; Derekas, Alíz; Henning, Thomas; Kinemuchi, Karen; Kóspál, Ágnes; Kovács, József; Pál, András; Sarkis, Paula; Seli, Bálint; Szabó, Zsófia M.; Takáts, Katalin
    Extreme debris disks (EDDs) are rare systems with peculiarly large amounts of warm dust that may stem from recent giant impacts between planetary embryos during the final phases of terrestrial planet growth. Here we report on the identification and characterization of six new EDDs. These disks surround F5-G9 type main-sequence stars with ages >100 Myr, have dust temperatures higher than 300 K, and fractional luminosities between 0.01 and 0.07. Using time-domain photometric data at 3.4 and 4.6 μm from the WISE all-sky surveys, we conclude that four of these disks exhibited variable mid-infrared (IR) emission between 2010 and 2019. Analyzing the sample of all known EDDs, now expanded to 17 objects, we find that 14 of them showed changes at 3-5 μm over the past decade, suggesting that mid-IR variability is an inherent characteristic of EDDs. We also report that wide-orbit pairs are significantly more common in EDD systems than in the normal stellar population. While current models of rocky planet formation predict that the majority of giant collisions occur in the first 100 Myr, we find that the sample of EDDs is dominated by systems older than this age. This raises the possibility that the era of giant impacts may be longer than we think, or that some other mechanism(s) can also produce EDDs. We examine a scenario where the observed warm dust stems from the disruption and/or collisions of comets delivered from an outer reservoir into the inner regions, and explore what role the wide companions could play in this process.
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    HD 213885b: A transiting 1-d-period super-Earth with an Earth-like composition around a bright (V = 7.9) star unveiled by TESS
    (Oxford University Press, 2020-01-01) Espinoza, Néstor; Brahm, Rafael; Henning, Thomas; Jordán, Andrés; Dorn, Caroline; Rojas, Felipe; Sarkis, Paula; Kossakowski, Diana; Schlecker, Martin; Díaz, Matías R.; Jenkins, James S.; Aguilera-Gomez, Claudia; Jenkins, Jon M.; Twicken, Joseph D.; Collins, Karen A.; Lissauer, Jack; Armstrong, David J.; Adibekyan, Vardan; Barrado, David; Barros, Susana C.C.; Battley, Matthew; Bayliss, Daniel; Bouchy, François; Bryant, Edward M.; Cooke, Benjamin F.; Olivier D.S.; Dumusque, Xavier; Figueira, Pedro; Giles, Helen; Lillo-Box, Jorge; Lovis, Christophe; Nielsen, Louise D.; Pepe, Francesco; Pollacco, Don; Santos, Nuno C.; Sousa, Sergio G.; Udry, Stéphane; Wheatley, Peter J.; Turner, Oliver; Marmier, Maxime; Ségransan, Damien; Ricker, George; Latham, David; Seager, Sara; Winn, Joshua N.; Kielkopf, John F.; Hart, Rhodes; Wingham, Geof; Jensen, Eric L.N.; Hełminiak, Krzysztof G.; Tokovinin A.; Briceño C.; Ziegler, Carl; Law, Nicholas M.; Mann, Andrew W.; Daylan, Tansu; Doty, John P.; Guerrero, Natalia; Boyd, Patricia; Crossfield, Ian
    We report the discovery of the 1.008-d, ultrashort period (USP) super-Earth HD 213885b (TOI-141b) orbiting the bright (V= 7.9) star HD 213885 (TOI-141, TIC 403224672), detected using photometry from the recently launched TESS mission. Using FEROS, HARPS, and CORALIE radial velocities, we measure a precise mass of 8.8 ±0.6M⊙ for this 1.74±0.05R⊙ exoplanet, which provides enough information to constrain its bulk composition - similar to Earth's but enriched in iron. The radius, mass, and stellar irradiation of HD 213885b are, given our data, very similar to 55 Cancri e, making this exoplanet a good target to perform comparative exoplanetology of short period, highly irradiated super-Earths. Our precise radial velocities reveal an additional 4.78-d signal which we interpret as arising from a second, non-transiting planet in the system, HD 213885c, whose minimum mass of 19.9 ± 1.4 M⊙ makes it consistent with being a Neptune-mass exoplanet. The HD 213885 system is very interesting from the perspective of future atmospheric characterization, being the second brightest star to host an USP transiting super-Earth (with the brightest star being, in fact, 55 Cancri). Prospects for characterization with present and future observatories are discussed.