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 semi-automatic procedure for abundance determination of A- and F-type stars 2009MNRAS.396.1689H
    Turbulent eddy-time-correlation in the solar convective zone 2010A&A...522L...2B
    A Seismic Signature of a Second Dynamo? 2010ApJ...718L..19F
    Seismic signatures of stellar cores of solar-like pulsators: Dependence on mass and age 2010AN....331..940B
    Mode visibilities in radial velocity and photometric Sun-as-a-star helioseismic observations 2011A&A...528A..25S
    Search for radial velocity variations in eight M-dwarfs with NIRSPEC/Keck II 2012A&A...538A.141R
    The quest for the solar g modes 2010A&ARv..18..197A
    The quasi-biennial periodicity (QBP) in velocity and intensity helioseismic observations. The seismic QBP over solar cycle 23 2012A&A...539A.135S
    On the Solar Origin of the Signal at 220.7 μHz: A Possible Component of a g-Mode? 2009ApJS..184..288J
    Acoustic power absorption and enhancement generated by slow and fast MHD waves. Evidence of solar cycle velocity/intensity amplitude changes consistent with the mode conversion theory 2010A&A...516A..30S
    Doppler tomography of transiting exoplanets: a prograde, low-inclined orbit for the hot Jupiter CoRoT-11b 2012A&A...543L...5G
    Characterization of the HD 17156 planetary system 2009A&A...503..601B
    Absolute parameters of the Algol binary Z Vul 2009NewA...14..528L
    The impact of seismicity on high angular resolution astronomy: the case of El Teide Observatory, Canary Islands 2008SPIE.7012E.102E
    Unusual high-frequency oscillations in the Kepler δ Scuti star KIC 4840675 2012MNRAS.424.1187B
    The γ Doradus CoRoT target HD 49434. I. Results from the ground-based campaign 2008A&A...489.1213U
    The Kepler characterization of the variability among A- and F-type stars. I. General overview 2011A&A...534A.125U
    The excitation of solar-like oscillations in a δSct star by efficient envelope convection 2011Natur.477..570A
    Photometric multi-site campaign on massive B stars in the open cluster χ Persei (NGC 884) 2008JPhCS.118a2071S
    Looking for a Connection between the Am Phenomenon and Hybrid δ Sct -γ Dor Pulsation: Determination of the Fundamental Parameters and Abundances of HD 114839 and BD +18 4914 2011ApJ...743..153H
    Ground-based observations of the β Cephei CoRoT main target HD 180 642: abundance analysis and mode identification 2009A&A...506..269B
    Ground-based observations of the beta Cephei CoRoT main target HD 180642 2009CoAst.158..292B
    Ground-based observations of O and B stars 2009CoAst.158..156U
    Close-up of primary and secondary asteroseismic CoRoT targets and the ground-based follow-up observations 2008JPhCS.118a2077U
    An asteroseismic study of the β Cephei star 12 Lacertae: multisite spectroscopic observations, mode identification and seismic modelling 2009MNRAS.396.1460D
    A multisite photometric study of two unusual β Cep stars: the magnetic V2052 Oph and the massive rapid rotator V986 Oph 2012MNRAS.424.2380H
    The Lupus Transit Survey for Hot Jupiters: Results and Lessons 2009AJ....137.4368B
    Searching for transits in data with long time baselines and poor sampling 2011A&A...529A...6T
    Verification of the Kepler Input Catalog from Asteroseismology of Solar-type Stars 2011ApJ...738L..28V
    Unveiling stellar magnetic activity using CoRoT seismic observations 2011JPhCS.271a2045M
    The solar-like CoRoT target HD 170987: spectroscopic and seismic observations 2010A&A...518A..53M
    The CoRoT target HD 175726: an active star with weak solar-like oscillations 2009A&A...506...33M
    solarFLAG hare and hounds: estimation of p-mode frequencies from Sun-as-star helioseismology data 2008MNRAS.389.1780J
    Solar-like oscillations in red giants observed with Kepler: comparison of global oscillation parameters from different methods 2011A&A...525A.131H
    Solar-like Oscillations in KIC 11395018 and KIC 11234888 from 8 Months of Kepler Data 2011ApJ...733...95M
    Solar-like oscillations in HD 181420: data analysis of 156 days of CoRoT data 2009A&A...506...51B
    Seismic Evidence for a Rapidly Rotating Core in a Lower-giant-branch Star Observed with Kepler 2012ApJ...756...19D
    Radius Determination of Solar-type Stars Using Asteroseismology: What to Expect from the Kepler Mission 2009ApJ...700.1589S
    Predicting the Detectability of Oscillations in Solar-type Stars Observed by Kepler 2011ApJ...732...54C
    Oscillation mode frequencies of 61 main-sequence and subgiant stars observed by Kepler 2012A&A...543A..54A
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