Huber, Daniel;
White, Timothy R;
Metcalfe, Travis S;
Chontos, Ashley;
Fausnaugh, Michael M;
Ho, Cynthia SK;
Van Eylen, Vincent;
... Winn, Joshua N; + view all
(2022)
A 20 Second Cadence View of Solar-type Stars and Their Planets with TESS: Asteroseismology of Solar Analogs and a Recharacterization of π Men c.
The Astronomical Journal
, 163
(2)
, Article 79. 10.3847/1538-3881/ac3000.
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Abstract
We present an analysis of the first 20 second cadence light curves obtained by the TESS space telescope during its extended mission. We find improved precision of 20 second data compared to 2 minute data for bright stars when binned to the same cadence (≈10%–25% better for T ≲ 8 mag, reaching equal precision at T ≈ 13 mag), consistent with pre-flight expectations based on differences in cosmic-ray mitigation algorithms. We present two results enabled by this improvement. First, we use 20 second data to detect oscillations in three solar analogs (γ Pav, ζ Tuc, and π Men) and use asteroseismology to measure their radii, masses, densities, and ages to ≈1%, ≈3%, ≈1%, and ≈20% respectively, including systematic errors. Combining our asteroseismic ages with chromospheric activity measurements, we find evidence that the spread in the activity–age relation is linked to stellar mass and thus the depth of the convection zone. Second, we combine 20 second data and published radial velocities to recharacterize π Men c, which is now the closest transiting exoplanet for which detailed asteroseismology of the host star is possible. We show that π Men c is located at the upper edge of the planet radius valley for its orbital period, confirming that it has likely retained a volatile atmosphere and that the "asteroseismic radius valley" remains devoid of planets. Our analysis favors a low eccentricity for π Men c (<0.1 at 68% confidence), suggesting efficient tidal dissipation (Q/k2,1 ≲ 2400) if it formed via high-eccentricity migration. Combined, these early results demonstrate the strong potential of TESS 20 second cadence data for stellar astrophysics and exoplanet science.
| Type: | Article |
|---|---|
| Title: | A 20 Second Cadence View of Solar-type Stars and Their Planets with TESS: Asteroseismology of Solar Analogs and a Recharacterization of π Men c |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3847/1538-3881/ac3000 |
| Publisher version: | http://dx.doi.org/10.3847/1538-3881/ac3000 |
| Language: | English |
| Additional information: | Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. |
| Keywords: | Science & Technology, Physical Sciences, Astronomy & Astrophysics, SUPER-NYQUIST ASTEROSEISMOLOGY, SPIN-ORBIT MISALIGNMENT, EXOPLANET-HOST STAR, POWERED MASS-LOSS, OSCILLATION FREQUENCIES, INITIAL CHARACTERISTICS, FUNDAMENTAL PROPERTIES, ROTATIONAL EVOLUTION, MODE OSCILLATIONS, MAGNETIC ACTIVITY |
| UCL classification: | UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics UCL > Provost and Vice Provost Offices > UCL BEAMS UCL |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10143644 |
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