TESS Asteroseismology of the Known Red-giant Host Stars HD 212771 and HD 203949

• Type: Article in International Scientific Journal
• Date: 2019

Authors

Campante, TL (Author) FCUP; Corsaro, E (Author) Other; Lund, MN (Author) Other; Mosser, B (Author) Other; Serenelli, A (Author) Other; Veras, D (Author) Other; Adibekyan, V (Author) Other; Antia, HM (Author) Other; Ball, W (Author) Other; Basu, S (Author) Other; Bedding, TR (Author) Other; Bossini, D (Author) Other; Davies, GR (Author) Other; Mena, ED (Author) FCUP; Garcia, RA (Author) Other; Handberg, R (Author) Other; Hon, M (Author) Other; Kane, SR (Author) Other; Kawaler, SD (Author) Other; Kuszlewicz, JS (Author) Other; Lucas, M (Author) Other; Mathur, S (Author) Other; Nardetto, N (Author) Other; Nielsen, MB (Author) Other; Pinsonneault, MH (Author) Other; Reffert, S (Author) Other; Aguirre, VS (Author) Other; Stassun, KG (Author) Other; Stello, D (Author) Other; Stock, S (Author) Other; Vrard, M (Author) Other; Yildiz, M (Author) Other; Chaplin, WJ (Author) Other; Huber, D (Author) Other; Bean, JL (Author) Other; Orhan, ZC (Author) Other; Cunha, MS (Author) FCUP; Christensen Dalsgaard, J (Author) Other; Kjeldsen, H (Author) Other; Metcalfe, TS (Author) Other; Miglio, A (Author) Other; Monteiro, MJPFG (Author) FCUP; Nsamba, B (Author) Other; Ortel, S (Author) Other; Pereira, F (Author) Other; Sousa, SG (Author) FCUP; Tsantaki, M (Author) Other; Turnbull, MC (Author) Other

Journal

Title: Astrophysical Journal

Vol. 885

Final page: 31

ISSN: 0004-637X

Publisher: American Astronomical Society

Indexing

ISI Web of Knowledge - 23 Citations

Scopus - 27 Citations

Other information

Authenticus ID: P-00R-DC5

DOI: 10.3847/1538-4357/ab44a8

Abstract (EN): The Transiting Exoplanet Survey Satellite (TESS) is performing a near all-sky survey for planets that transit bright stars. In addition, its excellent photometric precision enables asteroseismology of solar-type and red-giant stars, which exhibit convection-driven, solar-like oscillations. Simulations predict that TESS will detect solar-like oscillations in nearly 100 stars already known to host planets. In this paper, we present an asteroseismic analysis of the known red-giant host stars HD;212771 and HD;203949, both systems having a long-period planet detected through radial velocities. These are the first detections of oscillations in previously known exoplanet-host stars by TESS, further showcasing the mission?s potential to conduct asteroseismology of red-giant stars. We estimate the fundamental properties of both stars through a grid-based modeling approach that uses global asteroseismic parameters as input. We discuss the evolutionary state of HD;203949 in depth and note the large discrepancy between its asteroseismic mass (M-* = 1.23 0.15 MM* = 1.00 0.16 M if in the clump) and the mass quoted in the discovery paper (M-* = 2.1 0.1 M), implying a change >30% in the planet?s mass. Assuming HD;203949 to be in the clump, we investigate the planet?s past orbital evolution and discuss how it could have avoided engulfment at the tip of the red-giant branch. Finally, HD;212771 was observed by K2 during its Campaign 3, thus allowing for a preliminary comparison of the asteroseismic performances of TESS and K2. We estimate the ratio of the observed oscillation amplitudes for this star to be <i, consistent with the expected ratio of ?0.85 due to the redder bandpass of TESS.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12