Luminaries in the Sky: The TESS Legacy Sample of Bright Stars. I. Asteroseismic detections in naked-eye main-sequence and sub-giant solar-like oscillators

TL;DR

This work presents the TESS Luminaries Sample (TLS), a catalog of solar‑like oscillations detected in 196 bright naked‑eye MS/SG stars observed by TESS, including 128 new detections. Using 120‑s and 20‑s photometry, custom apertures, and the pySYD pipeline, the authors derive global asteroseismic parameters $ν_{ m max}$ and $Δν$ and validate them against independent pipelines and scaling relations, finding typical uncertainties of ~1.6% in $Δν$ and ~3.7% in $ν_{ m max}$. The study demonstrates that 20‑s cadence data yield lower high‑frequency noise, expanding the bright MS/SG seismic sample by over an order of magnitude and enabling robust ages for diverse applications, including PLATO and HWO calibrations, interferometric radius measurements, and exoplanetary system characterization. The TLS targets offer valuable benchmarks for stellar evolution modelling and provide a rich resource for future peak‑bagging and detailed stellar modelling, as well as cross‑disciplinary studies in interferometry, exoplanets, and debris disks. By mapping TLS overlap with PLATO LOP fields and HWO targets, the paper lays groundwork for precise stellar ages crucial for interpreting biosignatures in direct imaging campaigns and for refining stellar physics across a bright, nearby stellar population.

Abstract

We aim to detect and characterise solar-like oscillations in bright naked-eye (V<6) main-sequence (MS) and subgiant stars observed by TESS. We seek to expand the current benchmark sample of oscillators, provide accurate global asteroseismic parameters for these bright targets, and assess their potential for future detailed investigations -- including missions such as the HWO and PLATO. Our sample of bright stars was selected from the Hipparcos/Tycho catalogues. We analysed TESS 120-s and 20-s cadence photometry using SPOC light curves and custom apertures from target pixel files. After applying a filtering of the light curves, we extracted global asteroseismic parameters ($ν_{\rm max}$ and $Δν$) using the pySYD pipeline. Results were cross-validated with independent pipelines and compared to predictions from the ATL, while noise properties were evaluated to quantify improvements from a 20-s observing cadence. We detect solar-like oscillations in a total of 196 stars -- including 128 new detections -- with extracted $ν_{\rm max}$ and $Δν$ values showing strong conformity to expected scaling relations. This corresponds to an increase by more than an order of magnitude in the number of MS stars with detection of solar-like oscillations from TESS. Nearly 40% of our new detections are prime HWO targets, enabling systematic asteroseismic age determinations relevant for interpreting atmospheric biosignatures. Our analysis confirms that 20-s cadence data yields lower high-frequency noise levels compared to 120-s data. Moreover, the precise stellar parameters obtained through asteroseismology establish these bright stars as benchmarks for seismic investigations and provide useful constraints for refining stellar evolution models and for complementary analyses in interferometry, spectroscopy, and exoplanet characterisation.

Figures (15)

• Figure 1: HR-diagram showing the criteria for our selection of targets. The red line shows our limits on ${M}_V$ and $(B-V)$, and targets in the lower non-shaded region were selected for analysis. The marker colour indicates the $V$-band magnitude for the stars, while the marker size indicates the number of sectors TESS will have observed a given star in Cycle 6 (up to and including Sector 83). The stars in the top left shaded box are not expected to show solar-like oscillations and here we have not indicated $V$ nor the number of sectors. The stars in the top-right shaded region contain evolved stars that may well show solar-like oscillations -- these will be the subject of a future study.
• Figure 2: Example of the effect of adopting custom apertures, here for $\psi^1$ Dra A (TIC 441804568) as observed during Sector 15 in $120$-s cadence, where the SPOC aperture is missing several high-flux pixels. Similar apertures are seen for $\psi^1$ Dra A in other sectors. Left: The adopted aperture, shown with a black outline, combines the SPOC aperture in orange and the K2P$^2$ aperture in red. The green outline shows the aperture used to estimate the background. In blue the median pixel flux levels are shown on a log-scale. Right: Segments of the power-density spectra of the filtered SAP light curves from the apertures on the left, where the PSD obtained from the SPOC aperture is shown in orange and the one from the adopted custom aperture is shown in red. The inset shows a zoom of the region with identified oscillations from the custom aperture data. The small inset to the right shows the échelle diagram of the zoomed region after correcting for the background using a robust Siegel slope estimator.
• Figure 3: Examples of PSD for a small subset of stars with detected oscillations, arranged according to increasing $\nu_{\rm max}$ (see Table \ref{['tab:all_seis']} for details). The spectra have been smoothed by an Epanechnikov kernel Epanechnikov with a width of $\Delta\nu\xspace/20$.
• Figure 4: Comparison of the TLS with solar-like detections in MS/SG stars from other missions. Left: position of solar-like oscillators in the HR-diagram, with an indication of the selection criteria in $M_{V}$ and $(B-V)$ used to define our sample (Sect. \ref{['sec:sample']}). The marker size indicates the $V$-band magnitude of the stars, while the marker edge colour indicates how or by which mission oscillations were first detected. Any stars with a detection of oscillations from this work are shown with a filled yellow marker. Stars with ground-based detections were identified from individual cases in the literature (see Table \ref{['tab:all_seis']} and Sect. \ref{['sec:comp']}); the Kepler comparison sample was constructed from the compilations of Lund2017, Serenelli2017, Mathur2022, in addition to Kepler-444 Campante2015 and $\theta$ Cyg Guzik2016; the 9 stars from CoRoT were identified from individual cases in the literature Barban2009Barban2013Appourchaux2008Mosser2009Mathur2010cMathur2013Ballot2011Boumier2014Castro2021; the stars forming the K2 sample are obtained from Keystone2016Keystone2024; while the TESS sample was obtained from the catalogues of Hatt2023, Zhou2024, and Corsaro2024, in addition to individual cases from the literature (see Table \ref{['tab:all_seis']}). For the TESS and K2 comparison samples, we have limited these to stars with $\nu_{\rm max}\xspace<284\,\mu\rm Hz$. Right: distribution of the stars in terms of distance and $\nu_{\rm max}$, using only stars that in the left plot fall within the $M_{V}$ and $(B-V)$ boundaries defined in our target selection. We note that $\alpha$ Cen A+B, at a distance of ${\sim}1.35$ pc, have been omitted from the plot. Distances and magnitudes used in this plot were adopted from the TESS Input Catalog TIC82_2021. The horizontal dashed line indicates the solar $\nu_{\rm max}$ for comparison.
• Figure 5: Left: correlation between the measured global asteroseismic parameters $\Delta\nu$ and $\nu_{\rm max}$. The dashed line indicate the empirical relation from Huber2011 together with the $1$- and $2$-$\sigma$ confidence bands on their relation. Right: KDE of the relative uncertainties on $\Delta\nu$ and $\nu_{\rm max}$ for the sample, with median values of ${\sim}1.6\%$ in $\Delta\nu$ and ${\sim}3.7\%$ in $\nu_{\rm max}$. The ticks at the bottom of the panel indicate the individual values, coloured according to the legend.