分类： 天文学 >> 天文学 提交时间： 2023-02-19
Chen Jiang
Tao Wu
Adina D. Feinstein
Keivan G. Stassun
Timothy R. Bedding
Dimitri Veras
Enrico Corsaro
Derek L. Buzasi
Dennis Stello
Yaguang Li
Savita Mathur
Rafael A. Garcia
Sylvain N. Breton
Mia S. Lundkvist
Przemyslaw J. Mikolajczyk
Charlotte Gehan
Tiago L. Campante
Diego Bossini
Stephen R. Kane
Jia Mian Joel Ong
摘要： The Transiting Exoplanet Survey Satellite (TESS) mission searches for new exoplanets. The observing strategy of TESS results in high-precision photometry of millions of stars across the sky, allowing for detailed asteroseismic studies of individual systems. In this work, we present a detailed asteroseismic analysis of the giant star HD 76920 hosting a highly eccentric giant planet ($e = 0.878$) with an orbital period of 415 days, using 5 sectors of TESS light curve that cover around 140 days of data. Solar-like oscillations in HD 76920 are detected around $52 \, \mu$Hz by TESS for the first time. By utilizing asteroseismic modeling that takes classical observational parameters and stellar oscillation frequencies as constraints, we determine improved measurements of the stellar mass ($1.22 \pm 0.11\, M_\odot$), radius ($8.68 \pm 0.34\,R_\odot$), and age ($5.2 \pm 1.4\,$Gyr). With the updated parameters of the host star, we update the semi-major axis and mass of the planet as $a=1.165 \pm 0.035$ au and $M_{\rm p}\sin{i} = 3.57 \pm 0.22\,M_{\rm Jup}$. With an orbital pericenter of $0.142 \pm 0.005$ au, we confirm that the planet is currently far away enough from the star to experience negligible tidal decay until being engulfed in the stellar envelope. We also confirm that this event will occur within about 100\,Myr, depending on the stellar model used.
分类： 天文学 >> 天文学 提交时间： 2023-02-19
Emily Hatt
Martin B. Nielsen
William J. Chaplin
Warrick H. Ball
Guy R. Davies
Timothy R. Bedding
Derek L. Buzasi
Ashley Chontos
Daniel Huber
Cenk Kayhan
Yaguang Li
Timothy R. White
Chen Cheng
Travis S. Metcalfe
Dennis Stello
摘要： The Transiting Exoplanet Survey Satellite (TESS) mission has provided photometric light curves for stars across nearly the entire sky. This allows for the application of asteroseismology to a pool of potential solar-like oscillators that is unprecedented in size. We aim to produce a catalogue of solar-like oscillators observed by TESS in the 120-second and 20-second cadence modes. The catalogue is intended to highlight stars oscillating at frequencies above the TESS 30-minute cadence Nyquist frequency with the purpose of encompassing the main sequence and subgiant evolutionary phases. We aim to provide estimates for the global asteroseismic parameters $\nu_{\mathrm{max}}$ and $\Delta\nu$. We apply a new probabilistic detection algorithm to the 120-second and 20-second light curves of over 250,000 stars. This algorithm flags targets that show characteristic signatures of solar-like oscillations. We manually vet the resulting list of targets to confirm the presence of solar-like oscillations. Using the probability densities computed by the algorithm, we measure the global asteroseismic parameters $\nu_{\mathrm{max}}$ and $\Delta\nu$. We produce a catalogue of 4,177 solar-like oscillators, reporting $\Delta\nu$ and $\nu_{\mathrm{max}}$ for $98\%$ of the total star count. The asteroseismic data reveals vast coverage of the HR diagram, populating the red giant branch, the subgiant regime and extending toward the main sequence. A crossmatch with external catalogs shows that 25 of the detected solar-like oscillators are a component of a spectroscopic binary, and 28 are confirmed planet host stars. These results provide the potential for precise, independent asteroseismic constraints on these and any additional TESS targets of interest.
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