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. Beck et al. (2024, A&A, 682, A7) increased the number of known solar-like oscillators in binary systems by about an order of magnitude. Such large sample allowed us to study the effects co-evolution of stellar evolution on the evolution of the binary orbits. Featured as "ESA Gaia image of the Week".
    2. Following the participation to the roadmaps in astrophysics for the ESA’s Human and Robotic Exploration Directorate in 2021, a paper in npj Microgravity was published where the key quetions in stellar physics were exposed along with proposed experiments for the future as part of that program (Mathur & Santos 2024).
    3. Merc et al. (2024, A&A, 683, A84) presented the first analysis of accretion-induced flickering variability in symbiotic binary stars from TESS lightcurves. This study significantly enlarged the known sample with such variability. This suggests that accretion disks are common in symbiotic stars.
    4. Solar magnetic activity in cycles 23&24 were analyzed by tracking GOLF low-degree p-mode frequency shifts across 3 bands, probing depths of 74–1575 km. Results suggest magnetic variations mainly occur near the surface. In cycle 24, shifts appeared earlier at high latitudes and coincided with surface activity near the equator, with stronger shifts at shallower depths.

    Related publications

    TOI-2084 b and TOI-4184 b: Two new sub-Neptunes around M dwarf stars 2023A&A...677A..38B
    TOI-1416: A system with a super-Earth planet with a 1.07 d period 2023A&A...677A..12D
    Everything that glitters is not gold: V1315 Cas is not a dormant black hole 2023MNRAS.524.5749Z
    TOI-1130: A photodynamical analysis of a hot Jupiter in resonance with an inner low-mass planet 2023A&A...675A.115K
    Unresolved Rossby and gravity modes in 214 A and F stars showing rotational modulation 2023MNRAS.524.4196H
    Magnetic Activity Evolution of Solar-like Stars. I. S <SUB>ph</SUB>-Age Relation Derived from Kepler Observations 2023ApJ...952..131M
    The planetary system around HD 190622 (TOI-1054). Measuring the gas content of low-mass planets orbiting F-stars 2023A&A...675A.183C
    Solar-like oscillations in γ Cephei A as seen through SONG and TESS. A seismic study of γ Cephei A 2023A&A...675A.197K
    FX UMa: A New Heartbeat Binary System with Linear and Nonlinear Tidal Oscillations and δ Sct Pulsations 2023AJ....166...42W
    The breakdown of current gyrochronology as evidenced by old coeval stars 2023MNRAS.523.5947S
    Pyodine: an open, flexible reduction software for iodine-calibrated precise radial velocities 2023A&A...674A.164H
    TOI-733 b: A planet in the small-planet radius valley orbiting a Sun-like star 2023A&A...674A.117G
    Multi-campaign asteroseismic analysis of eight solar-like pulsating stars observed by the K2 mission 2023A&A...674A.106G
    TOI-5678b: A 48-day transiting Neptune-mass planet characterized with CHEOPS and HARPS★ 2023A&A...674A..43U
    Refined parameters of the HD 22946 planetary system and the true orbital period of planet d★ 2023A&A...674A..44G
    TESS and CHEOPS discover two warm sub-Neptunes transiting the bright K-dwarf HD 15906 2023MNRAS.523.3090T
    Two warm Neptunes transiting HIP 9618 revealed by TESS and Cheops 2023MNRAS.523.3069O
    A new dynamical modeling of the WASP-47 system with CHEOPS observations 2023A&A...673A..42N
    Revisiting the Red Giant Branch Hosts KOI-3886 and ι Draconis. Detailed Asteroseismic Modeling and Consolidated Stellar Parameters 2023AJ....165..214C
    Temporal variation of the photometric magnetic activity for the Sun and Kepler solar-like stars 2023A&A...672A..56S
    A super-Earth and a mini-Neptune near the 2:1 MMR straddling the radius valley around the nearby mid-M dwarf TOI-2096 2023A&A...672A..70P
    The geometric albedo of the hot Jupiter HD 189733b measured with CHEOPS 2023A&A...672A..24K
    Glancing through the debris disk: Photometric analysis of DE Boo with CHEOPS 2023A&A...671A.127B
    A full transit of v<SUP>2</SUP> Lupi d and the search for an exomoon in its Hill sphere with CHEOPS 2023A&A...671A.154E
    TOI-836: A super-Earth and mini-Neptune transiting a nearby K-dwarf 2023MNRAS.520.3649H
    TOI-1055 b: Neptunian planet characterised with HARPS, TESS, and CHEOPS 2023A&A...671L...8B
    Hint of an exocomet transit in the CHEOPS light curve of HD 172555 2023A&A...671A..25K
    TESS Asteroseismic Analysis of HD 76920: The Giant Star Hosting an Extremely Eccentric Exoplanet 2023ApJ...945...20J
    Rotational modulation in A and F stars: magnetic stellar spots or convective core rotation? 2023MNRAS.520..216H
    Connecting photometric and spectroscopic granulation signals with CHEOPS and ESPRESSO 2023A&A...670A..24S
    Examining the orbital decay targets KELT-9 b, KELT-16 b, and WASP-4b, and the transit-timing variations of HD 97658 b 2023A&A...669A.124H
    Radial velocity confirmation of a hot super-Neptune discovered by TESS with a warm Saturn-mass companion 2023MNRAS.519.5637K
    55 Cancri e's occultation captured with CHEOPS 2023A&A...669A..64D
    The EBLM project - IX. Five fully convective M-dwarfs, precisely measured with CHEOPS and TESS light curves 2023MNRAS.519.3546S
    Discovery of TOI-1260d and the characterization of the multiplanet system 2023MNRAS.519.1437L
    HD 20329b: An ultra-short-period planet around a solar-type star found by TESS 2022A&A...668A.158M
    On the Characterization of GJ 504: A Magnetically Active Planet-host Star Observed by the Transiting Exoplanet Survey Satellite (TESS) 2022ApJ...940...93D
    Spinning up the Surface: Evidence for Planetary Engulfment or Unexpected Angular Momentum Transport? 2022ApJ...940...23T
    Hunting for anti-solar differentially rotating stars using the Rossby number. An application to the Kepler field 2022A&A...667A..50N
    TOI-2196 b: Rare planet in the hot Neptune desert transiting a G-type star 2022A&A...666A.184P
    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