Helio and Astero-Seismology and Exoplanets Search

    General
    Description

    The principal objectives of this project are: 1) to study the structure and dynamics of the solar interior, 2) to extend this study to other stars (either single or in binary systems), 3) to search for extrasolar planets using photometric methods (primarily by transits of their host stars) and their characterization with complementary radial velocity information.

    To reach our first objective, we use Helioseismology (analysis of the solar oscillation eigenmodes), a technique that enables us to infer the Sun's internal structure and dynamics with high accuracy. This project covers the various aspects necessary to attain the aforementioned objectives: instrumental and observational (with the international networks BiSON and GONG operating at the ”SolarLab” at Observatorio del Teide), reduction, analysis, and interpretation of data (in particular, the GOLF and VIRGO instruments aboard   ESA/SoHO satellite). Finally, theoretical developments in inversion techniques are carried out.

    Furthermore, Asteroseismology applies similar techniques to other oscillating stars to infer their evolutionary state as well as their internal structure and dynamics. Thanks to the high-quality photometric data collected by the CoRoT, Kepler, and TESS space missions, it is possible to extract global seismic parameters for hundreds of thousands of solar-like stars, from the main sequence through the red-giant phase. Stellar evolution models are used to find the model that best fits the observables (spectroscopic and individual mode frequencies), providing precise mass, radius, and age for the star. Binary stars provide additional strong constraints on these models and therefore allow testing the intricacies of internal stellar physics.

    Precise exoplanet characterization is critically dependent on an accurate knowledge of the host star. In particular, a reliable determination of the stellar age is required to constrain the age and evolutionary state of the planetary system, and to place robust limits on long-term habitability. At the interface between asteroseismology and exoplanet science, detailed seismic modeling of host stars is used to refine the ages of planetary systems. Strong involvement is ensured in the preparation of the ESA PLATO mission (launch expected at the end of 2026), including light-curve calibration, contributions to the science calibration and validation input catalog (scvPIC), proposals for complementary science, and ground-based follow-up observations.

    For this project, ground-based observations with the observational facilities available to IAC researchers, in particular at OCAN (Observatorios de Canarias), are key. In particular, ongoing observations with the ground-based, high-precision spectrographs on the SONG (Stellar Observations Network Group) and the Las Cumbres Observatory Network (LCO) are being conducted to improve the spectroscopic and seismic characterization of oscillating stars and to identify binary systems.

    Principal investigator

    Milestones

    1. We produced and published a state-of-the-art characterization of the stars observed by the Kepler mission in terms of their color-magnitude diagram (CMD) and binarity using data from Gaia DR3 (Godoy-Rivera et al. 2026, A&A, 696, A243)
    2. In Grossmann et al. (2025, A&A, 696, A42) we used asteroseismic and binary constraints to model the red giant binary system KIC 9163796. We successfully determined the age of the system with a relative precision of less than 10%. We thereby showed that combining asteroseismology with constraints from binarity can significantly improve age precision.
    3. The study of the magnetic activity of more than 50,000 solar-like stars observed by the Kepler mission was published (Mathur et al. 2025, ApJ, 982, 11). The analysis showed different behaviours of the evolution of magnetic activity with spectral type. This work highlights that the level of magnetic activity of the Sun is similar to its peers.
    4. We studied the recent photometric evolution of the symbiotic recurrent nova T CrB, eagerly awaited to erupt by the community. We showed that the proposed observational indicators do not reliably predict the outburst, which may occur even without a clear precursor (Merc et al., MNRAS Letters, 541, L14).

    Related publications

    The K2 Galactic Archaeology Program Data Release 2: Asteroseismic Results from Campaigns 4, 6, and 7 2020ApJS..251...23Z
    What future awaits the Sun? 2020Sci...368..466S
    The hot dayside and asymmetric transit of WASP-189 b seen by CHEOPS 2020A&A...643A..94L
    Robust asteroseismic properties of the bright planet host HD 38529 2020MNRAS.499.6084B
    The TOI-763 system: sub-Neptunes orbiting a Sun-like star 2020MNRAS.498.4503F
    π Earth: A 3.14 day Earth-sized Planet from K2's Kitchen Served Warm by the SPECULOOS Team 2020AJ....160..172N
    The Evolution of Rotation and Magnetic Activity in 94 Aqr Aa from Asteroseismology with TESS 2020ApJ...900..154M
    K2-280 b - a low density warm sub-Saturn around a mildly evolved star 2020MNRAS.497.4423N
    Rotation of Solar Analogs Crossmatching Kepler and Gaia DR2 2020ApJ...898..173D
    The Sixth Data Release of the Radial Velocity Experiment (RAVE). II. Stellar Atmospheric Parameters, Chemical Abundances, and Distances 2020AJ....160...83S
    The Sixth Data Release of the Radial Velocity Experiment (RAVE). I. Survey Description, Spectra, and Radial Velocities 2020AJ....160...82S
    The Multiplanet System TOI-421 2020AJ....160..114C
    Asteroseismic masses of four evolved planet-hosting stars using SONG and TESS: resolving the retired A-star mass controversy 2020MNRAS.496.5423M
    Precise mass and radius of a transiting super-Earth planet orbiting the M dwarf TOI-1235: a planet in the radius gap? 2020A&A...639A.132B
    An eclipsing substellar binary in a young triple system discovered by SPECULOOS 2020NatAs...4..650T
    The 16th Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra 2020ApJS..249....3A
    The CARMENES search for exoplanets around M dwarfs. A super-Earth planet orbiting HD 79211 (GJ 338 B) 2020A&A...637A..93G
    Spectroscopic and Asteroseismic Analysis of the Secondary Clump Red Giant HD 226808 2020ApJ...894...67D
    Doppler Imaging and Differential Rotation of σ<SUP>2</SUP> Coronae Borealis Using SONG 2020ApJ...893..164X
    Three planets transiting the evolved star EPIC 249893012: a hot 8.8-M<SUB>⊕</SUB> super-Earth and two warm 14.7 and 10.2-M<SUB>⊕</SUB> sub-Neptunes 2020A&A...636A..89H
    TOI-503: The First Known Brown-dwarf Am-star Binary from the TESS Mission 2020AJ....159..151S
    Age dating of an early Milky Way merger via asteroseismology of the naked-eye star ν Indi 2020NatAs...4..382C
    TESS Spots a Hot Jupiter with an Inner Transiting Neptune 2020ApJ...892L...7H
    Transiting exoplanets from the CoRoT space mission. XXIX. The hot Jupiters CoRoT-30 b and CoRoT-31 b 2020A&A...635A.122B
    TOI-132 b: A short-period planet in the Neptune desert transiting a V = 11.3 G-type star<SUP>★</SUP> 2020MNRAS.493..973D
    It Takes Two Planets in Resonance to Tango around K2-146 2020AJ....159..120L
    Mass determinations of the three mini-Neptunes transiting TOI-125 2020MNRAS.492.5399N
    Detection and Characterization of Oscillating Red Giants: First Results from the TESS Satellite 2020ApJ...889L..34A
    Measurement of Atmospheric Scintillation during a Period of Saharan Dust (Calima) at Observatorio del Teide, Iz̃ana, Tenerife, and the Impact on Photometric Exposure Times 2020PASP..132c4501H
    Chemical Evolution in the Milky Way: Rotation-based Ages for APOGEE-Kepler Cool Dwarf Stars 2020ApJ...888...43C
    Core─Envelope Coupling in Intermediate-mass Core-helium Burning Stars 2019ApJ...887..203T
    TESS Asteroseismology of the Known Red-giant Host Stars HD 212771 and HD 203949 2019ApJ...885...31C
    Surface Rotation and Photometric Activity for Kepler Targets. I. M and K Main-sequence Stars 2019ApJS..244...21S
    Signatures of Magnetic Activity: On the Relation between Stellar Properties and p-mode Frequency Variations 2019ApJ...883...65S
    A giant impact as the likely origin of different twins in the Kepler-107 exoplanet system 2019NatAs...3..416B
    The K2 Galactic Caps Project - going beyond the Kepler field and ageing the Galactic disc 2019MNRAS.490.4465R
    Multicolour photometry for exoplanet candidate validation 2019A&A...630A..89P
    Revisiting the impact of stellar magnetic activity on the detection of solar-like oscillations by Kepler 2019FrASS...6...46M
    Masses and ages for metal-poor stars. A pilot programme combining asteroseismology and high-resolution spectroscopic follow-up of RAVE halo stars 2019A&A...627A.173V
    Greening of the brown-dwarf desert. EPIC 212036875b: a 51 MJ object in a 5-day orbit around an F7 V star 2019A&A...628A..64P
    Related projects
    Componentes del experimento PLATO
    PLATO (PLAnetary Transits and Oscillations of stars)
    PLAnetary Transits and Oscillations of stars (PLATO) is the third medium-class mission in ESA's Cosmic Vision programme. Its objective is to find and study a large number of extrasolar planetary systems, with emphasis on the properties of terrestrial planets in the habitable zone around solar-like stars
    Hans Jörg
    Deeg Deeg