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

    Displaying 401 - 440 of 516
    Kepler-21b: A 1.6 R Earth Planet Transiting the Bright Oscillating F Subgiant Star HD 179070 2012ApJ...746..123H
    Granulation in Red Giants: Observations by the Kepler Mission and Three-dimensional Convection Simulations 2011ApJ...741..119M
    Global asteroseismic properties of solar-like oscillations observed by Kepler: a comparison of complementary analysis methods 2011MNRAS.415.3539V
    Fundamental properties of five Kepler stars using global asteroseismic quantities and ground-based observations 2012A&A...537A.111C
    First asteroseismic results from CoRoT 2008CoAst.156...73M
    Evidence for the Impact of Stellar Activity on the Detectability of Solar-like Oscillations Observed by Kepler 2011ApJ...732L...5C
    Ensemble Asteroseismology of Solar-Type Stars with the NASA Kepler Mission 2011Sci...332..213C
    Effect of line-of-sight inclinations on the observation of solar activity cycle: Lessons for CoRoT & Kepler 2011JPhCS.271a2056V
    Determining global parameters of the oscillations of solar-like stars 2010A&A...511A..46M
    Detection of Solar-like Oscillations from Kepler Photometry of the Open Cluster NGC 6819 2010ApJ...713L.182S
    CoRoT sounds the stars: p-mode parameters of Sun-like oscillations on HD 49933 2008A&A...488..705A
    CoRoT Reveals a Magnetic Activity Cycle in a Sun-Like Star 2010Sci...329.1032G
    Calibrating Convective Properties of Solar-like Stars in the Kepler Field of View 2012ApJ...755L..12B
    Asteroseismology of the Solar Analogs 16 Cyg A and B from Kepler Observations 2012ApJ...748L..10M
    Asteroseismology of solar-type stars with Kepler I: Data analysis 2010AN....331..972K
    Asteroseismology from multi-month Kepler photometry: the evolved Sun-like stars KIC 10273246 and KIC 10920273 2011A&A...534A...6C
    Asteroseismic Diagrams from a Survey of Solar-like Oscillations with Kepler 2011ApJ...742L...3W
    AsteroFLAG: First results from hare-and-hounds Exercise #1 2008AN....329..549C
    AsteroFLAG — from the Sun to the stars 2008JPhCS.118a2048C
    Accurate p-mode measurements of the G0V metal-rich CoRoT target HD 52265 2011A&A...530A..97B
    Accurate fundamental parameters and detailed abundance patterns from spectroscopy of 93 solar-type Kepler targets 2012MNRAS.423..122B
    About the p-mode frequency shifts in HD 49933 2011A&A...530A.127S
    A Uniform Asteroseismic Analysis of 22 Solar-type Stars Observed by Kepler 2012ApJ...749..152M
    A Precise Asteroseismic Age and Radius for the Evolved Sun-like Star KIC 11026764 2010ApJ...723.1583M
    A fresh look at the seismic spectrum of HD49933: analysis of 180 days of CoRoT photometry 2009A&A...507L..13B
    Solar-like oscillations with low amplitude in the CoRoT target HD 181906 2009A&A...506...41G
    Seismic and spectroscopic characterization of the solar-like pulsating CoRoT target HD 49385 2010A&A...515A..87D
    Green's Functions for Far-Side Seismic Images: A Polar-Expansion Approach 2010ApJ...711..853P
    Empirical Determination of Convection Parameters in White Dwarfs. I. Whole Earth Telescope Observations of EC14012-1446 2012ApJ...751...91P
    Angular momentum transfer between oscillations and rotation in subdwarf B hybrid pulsators 2011A&A...535A..96P
    The onset of solar cycle 24. What global acoustic modes are telling us 2009A&A...504L...1S
    The GOLF-NG prototype and the solar European perspective for cosmic vision 2015-2025 2008JPhCS.118a2044T
    The Asteroseismic Potential of Kepler: First Results for Solar-Type Stars 2010ApJ...713L.169C
    The Acoustic Cutoff Frequency of the Sun and the Solar Magnetic Activity Cycle 2011ApJ...743...99J
    p-mode power variation with solar atmosphere as observed in the Na D1 and K spectral lines 2008AN....329..494S
    HELAS IT-platform: A new tool for the European Helio- and Asteroseismology community. 2008CoAst.153..108J
    The pulsation modes of the pre-white dwarf PG 1159-035 2008A&A...477..627C
    The pulsating hot subdwarf Balloon 090100001: results of the 2005 multisite campaign 2009MNRAS.392.1092B
    Testing the evolution of the DB white dwarf GD 358: first results of a new approach using asteroseismology 2009A&A...493.1067G
    On the Possible Existence of Short-Period g-Mode Instabilities Powered by Nuclear-Burning Shells in Post-Asymptotic Giant Branch H-Deficient (PG1159-Type) Stars 2009ApJ...701.1008C
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