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Given the massive spectroscopic surveys and the Gaia mission, the Milky Way has turned into a unique laboratory to be explored using abundance ratios that show a strong dependency with time. Within this framework, the data provided through asteroseismology serve as a valuable complement. Yet, it has been demonstrated that chemical traits can not be used as universal relations across the Galaxy. To complete this picture, it is important to investigate the dependence on metallicity of the chemical ratios employed for inferring stellar ages. We aim to explore different combinations of neutron-capture, odd-Z and $\alpha$ elements as a function of age, particularly focusing on their metallicity dependence for a sample of 74 giant field stars. Using UVES observations, we derive atmospheric parameters and high-precision line by line chemical abundances (<0.04 dex) for the entire set of spectra. Stellar ages are inferred from astereoseismic information. By fitting chemical-age trends for three different metallicity groups, we estimated their dependence on metallicity. We found that the stronger chemical-age relations ([Zr/$\alpha$]) are not necessarily the ratios with the smaller dependence on metallicity ([Ce/$\alpha$] and [Ce/Eu]). We confirm the [n-capture/$\alpha$]-age trends for evolved stars, wherein the most significant correlation is evident in stars with solar-metallicity, gradually diminishing in stars with lower iron content. The lack of homogeneity within the metallicity range highlights the intricate nature of our Galaxy's star formation history and yield production. Metallicity dependence in s-process element yields and the impact of radial stellar migration challenge the reliability of using chemical abundances alone to date stars. These discoveries raise doubts about universally valid chemical clocks applicable across the entire Galaxy and its diverse metallicity ranges., Comment: 19 pages, 14 figures + Appendix (2 tables)

Fundamental stellar parameters such as mass and radius are some of the most important building blocks in astronomy, both when it comes to understanding the star itself and when deriving the properties of any exoplanet(s) they may host. Asteroseismology of solar-like oscillations allows us to determine these parameters with high precision. We investigate the solar-like oscillations of the red-giant-branch star $\gamma$ Cep A, which harbours a giant planet on a wide orbit. We did this by utilising both ground-based radial velocities from the SONG network and space-borne photometry from the NASA TESS mission. From the radial velocities and photometric observations, we created a combined power spectrum, which we used in an asteroseismic analysis to extract individual frequencies. We clearly identify several radial and quadrupole modes as well as multiple mixed, dipole modes. We used these frequencies along with spectroscopic and astrometric constraints to model the star, and we find a mass of $1.27^{+0.05}_{-0.07}$ M$_\odot$, a radius of $4.74^{+0.07}_{-0.08}$ R$_\odot$, and an age of $5.7^{+0.8}_{-0.9}$ Gyr. We then used the mass of $\gamma$ Cep A and our SONG radial velocities to derive masses for $\gamma$ Cep B and $\gamma$ Cep Ab of $0.328^{+0.009}_{-0.012}$ M$_\odot$ and $6.6^{+2.3}_{-2.8}$ M$_{\rm Jup}$, respectively., Comment: 17 pages, 13 figures, accepted for publication in A&A

We report the discovery and confirmation of the planetary system TOI-1288. This late G dwarf harbours two planets: TOI-1288 b and TOI-1288 c. We combine TESS space-borne and ground-based transit photometry with HARPS-N and HIRES high-precision Doppler measurements, which we use to constrain the masses of both planets in the system and the radius of planet b. TOI-1288~b has a period of $2.699835^{+0.000004}_{-0.000003}$ d, a radius of $5.24 \pm 0.09$ R$_\oplus$, and a mass of $42 \pm 3$ M$_\oplus$, making this planet a hot transiting super-Neptune situated right in the Neptunian desert. This desert refers to a paucity of Neptune-sized planets on short period orbits. Our 2.4-year-long Doppler monitoring of TOI-1288 revealed the presence of a Saturn-mass planet on a moderately eccentric orbit ($0.13^{+0.07}_{-0.09}$) with a minimum mass of $84 \pm 7$ M$_\oplus$ and a period of $443^{+11}_{-13}$ d. The 5 sectors worth of TESS data do not cover our expected mid-transit time for TOI-1288 c, and we do not detect a transit for this planet in these sectors., Comment: 16 pages, 17 figures, under review MNRAS

Asteroseismology is a powerful tool to infer fundamental stellar properties. The use of these asteroseismic-inferred properties in a growing number of astrophysical contexts makes it vital to understand their accuracy. Consequently, we performed a hare-and-hounds exercise where the hares simulated data for 6 artificial main-sequence stars and the hounds inferred their properties based on different inference procedures. To mimic a pipeline such as that planned for the PLATO mission, all hounds used the same model grid. Some stars were simulated using the physics adopted in the grid, others a different one. The maximum relative differences found (in absolute value) between the inferred and true values of the mass, radius, and age were 4.32 per cent, 1.33 per cent, and 11.25 per cent, respectively. The largest systematic differences in radius and age were found for a star simulated assuming gravitational settling, not accounted for in the model grid, with biases of -0.88 per cent (radius) and 8.66 per cent (age). For the mass, the most significant bias (-3.16 per cent) was found for a star with a helium enrichment ratio outside the grid range. Moreover, a ~7 per cent dispersion in age was found when adopting different prescriptions for the surface corrections or shifting the classical observations by $\pm 1\sigma$. The choice of the relative weight given to the classical and seismic constraints also impacted significantly the accuracy and precision of the results. Interestingly, only a few frequencies were required to achieve accurate results on the mass and radius. For the age the same was true when at least one $l=2$ mode was considered., Comment: Accepted for publication in the Monthly Notices of the Royal Astronomical Society

We introduce the public version of the BAyesian STellar Algorithm (BASTA), an open-source code written in {\tt Python} to determine stellar properties based on a set of astrophysical observables. BASTA has been specifically designed to robustly combine large datasets that include asteroseismology, spectroscopy, photometry, and astrometry. We describe the large number of asteroseismic observations that can be fit by the code and how these can be combined with atmospheric properties (as well as parallaxes and apparent magnitudes), making it the most complete analysis pipeline available for oscillating main-sequence, subgiant, and red giant stars. BASTA relies on a set of pre-built stellar isochrones or a custom-designed library of stellar tracks which can be further refined using our interpolation method (both along and across stellar tracks/isochrones). We perform recovery tests with simulated data that reveal levels of accuracy at the few percent level for radii, masses, and ages when individual oscillation frequencies are considered, and show that asteroseismic ages with statistical uncertainties below 10% are within reach if our stellar models are reliable representations of stars. BASTA is extensively documented and includes a suite of examples to support easy adoption and further development by new users., Comment: 21 pages, 14 figures, resubmitted after positive referee report. The code is available at https://github.com/BASTAcode/BASTA