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

    A survey for pulsating subdwarf B stars with the Nordic Optical Telescope 2010A&A...513A...6O
    A peculiar Of star in the Local Group galaxy IC 1613 2012A&A...543A..85H
    Update on g-mode research 2008AN....329..476G
    The solar core as never seen before 2011JPhCS.271a2043E
    The rotation rate and its evolution derived from improved mode fitting and inversion methodology 2011JPhCS.271a2067K
    Sensitivity of helioseismic gravity modes to the dynamics of the solar core 2008A&A...484..517M
    New insights on the solar core 2011JPhCS.271a2046G
    Influence of Low-Degree High-Order p-Mode Splittings on the Solar Rotation Profile 2008SoPh..251..119G
    HD 172189: another step in furnishing one of the best laboratories known for asteroseismic studies 2009A&A...507..901C
    Detection and temporal coherence of p-modes below 1.4 mHz 2008AN....329..470E
    Comparative analysis of the impact of geological activity on the structural design of telescope facilities in the Canary Islands, Hawaii and Chile 2010MNRAS.407.1361E
    Analysis of the Sensitivity of Solar Rotation to Helioseismic Data from GONG, GOLF, and MDI Observations 2008ApJ...679.1636E
    Advances in solar rotation rate inferences: Unstructured grid inversions and improved rotational splittings 2010AN....331..890E
    Accurate Mapping of the Torsional Oscillations: a Trade-Off Study between Time Resolution and Mode Characterization Precision 2011JPhCS.271a2078E
    A devil in the detail: parameter cross-talk from the solar cycle and estimation of solar p-mode frequencies 2008MNRAS.385.1605C
    Using Stellar Densities to Evaluate Transiting Exoplanetary Candidates 2011ApJ...726..112T
    Transiting exoplanets from the CoRoT space mission. XXIII. CoRoT-21b: a doomed large Jupiter around a faint subgiant star 2012A&A...545A...6P
    Transiting exoplanets from the CoRoT space mission. XXII. CoRoT-16b: a hot Jupiter with a hint of eccentricity around a faint solar-like star 2012A&A...541A.149O
    Transiting exoplanets from the CoRoT space mission. XXI. CoRoT-19b: a low density planet orbiting an old inactive F9V-star 2012A&A...537A.136G
    Transiting exoplanets from the CoRoT space mission. XX. CoRoT-20b: A very high density, high eccentricity transiting giant planet 2012A&A...538A.145D
    Transiting exoplanets from the CoRoT space mission. XVIII. CoRoT-18b: a massive hot Jupiter on a prograde, nearly aligned orbit 2011A&A...533A.130H
    Transiting exoplanets from the CoRoT space mission. XVII. The hot Jupiter CoRoT-17b: a very old planet 2011A&A...531A..41C
    Transiting exoplanets from the CoRoT space mission. XVI. CoRoT-14b: an unusually dense very hot Jupiter 2011A&A...528A..97T
    Transiting exoplanets from the CoRoT space mission. XV. CoRoT-15b: a brown-dwarf transiting companion 2011A&A...525A..68B
    Transiting exoplanets from the CoRoT space mission. XIV. CoRoT-11b: a transiting massive ``hot-Jupiter'' in a prograde orbit around a rapidly rotating F-type star 2010A&A...524A..55G
    Transiting exoplanets from the CoRoT space mission. XII. CoRoT-12b: a short-period low-density planet transiting a solar analog star 2010A&A...520A..97G
    Transiting exoplanets from the CoRoT space mission. XI. CoRoT-8b: a hot and dense sub-Saturn around a K1 dwarf 2010A&A...520A..66B
    Transiting exoplanets from the CoRoT space mission. X. CoRoT-10b: a giant planet in a 13.24 day eccentric orbit 2010A&A...520A..65B
    Transiting exoplanets from the CoRoT space mission. VIII. CoRoT-7b: the first super-Earth with measured radius 2009A&A...506..287L
    Transiting exoplanets from the CoRoT space mission. VII. The ``hot-Jupiter''-type planet CoRoT-5b 2009A&A...506..281R
    Transiting exoplanets from the CoRoT space mission. V. CoRoT-Exo-4b: stellar and planetary parameters 2008A&A...488L..47M
    Transiting exoplanets from the CoRoT space mission. IX. CoRoT-6b: a transiting ``hot Jupiter'' planet in an 8.9d orbit around a low-metallicity star 2010A&A...512A..14F
    Transiting exoplanets from the CoRoT space mission. IV. CoRoT-Exo-4b: a transiting planet in a 9.2 day synchronous orbit 2008A&A...488L..43A
    Transiting exoplanets from the CoRoT space mission. III. The spectroscopic transit of CoRoT-Exo-2b with SOPHIE and HARPS 2008A&A...482L..25B
    Transiting exoplanets from the CoRoT space mission. II. CoRoT-Exo-2b: a transiting planet around an active G star 2008A&A...482L..21A
    Transiting exoplanets from the CoRoT space mission. I. CoRoT-Exo-1b: a low-density short-period planet around a G0V star 2008A&A...482L..17B
    Transiting exoplanets from the CoRoT space mission Resolving the nature of transit candidates for the LRa03 and SRa03 fields 2012Ap&SS.337..511C
    Transiting exoplanets from the CoRoT space mission . XIX. CoRoT-23b: a dense hot Jupiter on an eccentric orbit 2012A&A...537A..54R
    Transiting exoplanets from the CoRoT space mission . XIII. CoRoT-13b: a dense hot Jupiter in transit around a star with solar metallicity and super-solar lithium content 2010A&A...522A.110C
    Transiting exoplanets from the CoRoT space mission . VI. CoRoT-Exo-3b: the first secure inhabitant of the brown-dwarf desert 2008A&A...491..889D
    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