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, 3) to search for extrasolar planets using photometric methods (primarily by transits of their host stars) and their characterization (using radial velocity information) and 4) the study of the planetary atmospheres.

    To reach our first objective, we use Global Helioseismology (analysis of the solar oscillation eigenmodes) and Local Helioseismology (that uses travel waves). Solar seismology allows to accurately infer information about the internal structure and dynamics of the Sun,. This project covers the various necessary aspects to attain the aforementioned objectives: instrumental, observational, reduction, analysis and interpretation of data and, finally, theoretical developments of inversion techniques and development of structure and evolution models.

    On the other hand, the Astroseismology aims to obtain a similar knowledge of other stars. Thanks to the huge number of stars observed by CoRoT, Kepler and TESS space missions it is possible to extract seismic global parameters of hundreds of stars; both solar type and red giants. Furthermore, the recent deployment and beginning of observations with the high precision spectrographs of the SONG (Stellar Observations Network Group) ground-based telescopes will substantially improve the characterization of the eigenmodes spectrum in bright stars.

    The strategy of using planetary transits to discover new planets around other stars consists of the photometric detection of the dimming of the light of the star when one of its planets passes, or ‘transits’ in front of it. Currently this method is the preferred one for the study of small planets, not only due to its sensitivity, but also because this method allows a more detailed investigation of the planets found (e.g. Planetary atmospheres). This technique is similar to the one that is used for helio- and asteroseismology and so some of its methods are a logical extension from that. However, it is also important to develop new algorithms and observing methods for the unequivocal detection and analysis of planets and to be able to distinguish them from false alarms.

    The current horizon for studies of exoplanets with space missions involves new missions, beginning with the launch of CHEOPS, followed by TESS, JWST and in 2026, PLATO. Thus, there is presently a window of opportunity for ground-based facilities, and we are pursuing observations using mainly TNG, NOT y GTC.

    Principal investigator

    Milestones

    1. Members of the team (P. G. Beck, H. Deeg, S. Mathur, F. H. Perez, C. Regulo) were involved in the discovery and characterization of a warm Saturn transiting a slightly evolved solar-like star (HD 89345) observed with the NASA K2 mission and confirmed with RV measurements. The seismic analysis of the star led to precise estimates of the stellar parameters.
    2. P.G.Beck lead two papers on binary systems hosting red-giant binaries, using asteroseismic techniques and data from the Kepler space telescope. Beck et al (2018a,b) allow a better understanding of the stellar structure of the stellar components, and the tidal interaction in binary systems. The internal mixing was investigated through measurements lithium.
    3. S. Mathur participated in the analysis of the first planet discovered with the NASA TESS mission, orbiting the star Pi Men. The seismic analysis led to a very marginal detection but gave a hint of the asteroseismic potential with the TESS data (Gandolfi et al. 2018).
    4. Project "Solar-SONG". For the first time, stellar instrumentation (SONG spectrograph) has been used to obtain precise measurements of the radial velocity of the Sun with high temporal cadence (4 sec.) and long duration (57 consecutive days) to allow the detailed study of the spectrum of oscillations ( p-modes) and obtain their global parameters
    5. The researchers Hans J. Deeg and Juan Antonio Belmonte coordinated the edition of the "Handbook of Exoplanets", four volumes with 160 articles by more than 300 specialists in exoplanetology. Three years of intensive work have resulted in a complete documentation on the state of the art of the studies of the planets beyond the Solar System.

    Related publications

    • Transiting exoplanets from the CoRoT space mission. II. CoRoT-Exo-2b: a transiting planet around an active G star
      Context: The CoRoT mission, a pioneer in exoplanet searches from space, has completed its first 150 days of continuous observations of ~12 000 stars in the galactic plane. An analysis of the raw data identifies the most promising candidates and triggers the ground-based follow-up. Aims: We report on the discovery of the transiting planet CoRoT-Exo
      Alonso, R. et al.

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      5
      2008
      Citations
      204
    • Transiting exoplanets from the CoRoT space mission. I. CoRoT-Exo-1b: a low-density short-period planet around a G0V star
      Context: The pioneer space mission for photometric planet searches, CoRoT, steadily monitors about 12 000 stars in each of its fields of view. Transit candidates can be detected early in the processing of the data and before the end of a run of observation. Aims: We report the detection of the first planet discovered by CoRoT and characterizing it
      Barge, P. et al.

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      5
      2008
      Citations
      169
    • Transiting exoplanets from the CoRoT space mission Resolving the nature of transit candidates for the LRa03 and SRa03 fields
      CoRoT is a space telescope which aims at studying internal structure of stars and detecting extrasolar planets. We present here a list of transits detected in the light curves of stars observed by CoRoT in two fields in the anti-center direction: the LRa03 one observed during 148 days from 3 October 2009 to 1 March 2010 followed by the SRa03 one
      Cavarroc, C. et al.

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      2
      2012
      Citations
      16
    • Transiting exoplanets from the CoRoT space mission . XIX. CoRoT-23b: a dense hot Jupiter on an eccentric orbit
      We report the detection of CoRoT-23b, a hot Jupiter transiting in front of its host star with a period of 3.6314 ± 0.0001 days. This planet was discovered thanks to photometric data secured with the CoRoT satellite, combined with spectroscopic radial velocity (RV) measurements. A photometric search for possible background eclipsing binaries
      Rouan, D. et al.

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      1
      2012
      Citations
      16
    • 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
      We announce the discovery of the transiting planet CoRoT-13b. Ground-based follow-up in CFHT and IAC80 confirmed CoRoT's observations. The mass of the planet was measured with the HARPS spectrograph and the properties of the host star were obtained analyzing HIRES spectra from the Keck telescope. It is a hot Jupiter-like planet with an orbital
      Cabrera, J. et al.

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      11
      2010
      Citations
      45
    • Transiting exoplanets from the CoRoT space mission . VI. CoRoT-Exo-3b: the first secure inhabitant of the brown-dwarf desert
      Context: The CoRoT space mission routinely provides high-precision photometric measurements of thousands of stars that have been continuously observed for months. Aims: The discovery and characterization of the first very massive transiting planetary companion with a short orbital period is reported. Methods: A series of 34 transits was detected in
      Deleuil, M. et al.

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      12
      2008
      Citations
      196
    • Transit timing analysis of CoRoT-1b
      Context. CoRoT, the pioneer space-based transit search, steadily provides thousands of high-precision light curves with continuous time sampling over periods of up to 5 months. The transits of a planet perturbed by an additional object are not strictly periodic. By studying the transit timing variations (TTVs), additional objects can be detected in
      Csizmadia, Sz. et al.

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      2
      2010
      Citations
      20
    • The thermal emission of the young and massive planet CoRoT-2b at 4.5 and 8 μm
      We report measurements of the thermal emission of the young and massive planet CoRoT-2b at 4.5 and 8 μm with the Spitzer Infrared Array Camera (IRAC). Our measured occultation depths are 0.510±0.042% at 4.5 and 0.41±0.11% at 8 μm. In addition to the CoRoT optical measurements, these planet/star flux ratios indicate a poor heat distribution on the
      Gillon, M. et al.

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      2
      2010
      Citations
      108
    • The secondary eclipse of CoRoT-1b
      The transiting planet CoRoT-1b is thought to belong to the pM-class of planets, in which the thermal emission dominates in the optical wavelengths. We present a detection of its secondary eclipse in the CoRoT white channel data, whose response function goes from ~400 to ~1000 nm. We used two different filtering approaches, and several methods to
      Alonso, R. et al.

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      10
      2009
      Citations
      56
    • The SARS algorithm: detrending CoRoT light curves with Sysrem using simultaneous external parameters
      Surveys for exoplanetary transits are usually limited not by photon noise but rather by the amount of red noise in their data. In particular, although the CoRoT space-based survey data are being carefully scrutinized, significant new sources of systematic noises are still being discovered. Recently, a magnitude-dependant systematic effect was
      Ofir, Aviv et al.

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      5
      2010
      Citations
      34
    • The Orbital Phases and Secondary Transits of Kepler-10b. A Physical Interpretation Based on the Lava-ocean Planet Model
      The Kepler mission has made an important observation: the first detection of photons from a terrestrial planet by observing its phase curve (Kepler-10b). This opens a new field in exoplanet science: the possibility of obtaining information about the atmosphere and surface of rocky planets, objects of prime interest. In this Letter, we apply the
      Rouan, D. et al.

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      11
      2011
      Citations
      48
    • The Mass of CoRoT-7b
      The mass of CoRoT-7b, the first transiting super-Earth exoplanet, is still a subject of debate. A wide range of masses have been reported in the literature ranging from as high as 8 M ⊕ to as low as 2.3 M ⊕. This range in mass is largely due to the activity level of the star that contributes a significant amount of radial velocity (RV) "jitter" and
      Hatzes, Artie P. et al.

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      12
      2011
      Citations
      101
    • Removing systematics from the CoRoT light curves. I. Magnitude-dependent zero point
      This paper presents an analysis that searched for systematic effects within the CoRoT exoplanet field light curves. The analysis identified a systematic effect that modified the zero point of most CoRoT exposures as a function of stellar magnitude. We could find this effect only after preparing a set of learning light curves that were relatively
      Mazeh, T. et al.

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      10
      2009
      Citations
      24
    • Rate and nature of false positives in the CoRoT exoplanet search
      Context: The CoRoT satellite searches for planets by applying the transit method, monitoring up to 12 000 stars in the galactic plane for 150 days in each observing run. This search is contaminated by a large fraction of false positives, caused by different eclipsing binary configurations that might be confused with a transiting planet. Aims: We
      Almenara, J. M. et al.

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      10
      2009
      Citations
      47
    • Possible detection of phase changes from the non-transiting planet HD 46375b by CoRoT
      Context. The present work deals with the detection of phase changes in an exoplanetary system. HD 46375 is a solar analog known to host a non-transiting Saturn-mass exoplanet with a 3.0236 day period. It was observed by the CoRoT satellite for 34 days during the fall of 2008. Aims: We attempt to identify at optical wavelengths, the changing phases
      Gaulme, P. et al.

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      7
      2010
      Citations
      11
    • Planetary transit candidates in the CoRoT-SRc01 field
      Context. The space mission CoRoT is devoted to the analysis of stellar variability and the photometric detection of extrasolar planets. Aims: We present the list of planetary transit candidates detected in the first short run observed by CoRoT that targeted SRc01, towards the Galactic center in the direction of Aquila, which lasted from April to
      Erikson, A. et al.

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      3
      2012
      Citations
      23
    • Planetary transit candidates in the CoRoT LRa01 field
      Context. CoRoT is a pioneering space mission whose primary goals are stellar seismology and extrasolar planets search. Its surveys of large stellar fields generate numerous planetary candidates whose lightcurves have transit-like features. An extensive analytical and observational follow-up effort is undertaken to classify these candidates. Aims
      Carone, L. et al.

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      2
      2012
      Citations
      28
    • Planetary transit candidates in the CoRoT initial run: resolving their nature
      With the release of CoRoT lightcurves of the Initial Run IRa01, 50 transiting planetary candidates have been published in a companion paper. About twenty of them were identified as binary stars from the CoRoT lightcurve itself. Complementary observations were conducted for 29 candidates, including ground-based photometry and radial-velocity
      Moutou, C. et al.

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      10
      2009
      Citations
      29
    • Planetary transit candidates in CoRoT-LRc01 field
      Aims: We present here the list of planetary transit candidates detected in the first long run observed by CoRoT: LRc01, towards the galactic center in the direction of Aquila, which lasted from May to October 2007. Methods: we analyzed 3719 (33%) sources in the chromatic bands and 7689 in the monochromatic band. Instrumental noise and the stellar
      Cabrera, J. et al.

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      10
      2009
      Citations
      41
    • Planetary transit candidates in Corot-IRa01 field
      Context: CoRoT is a pioneering space mission devoted to the analysis of stellar variability and the photometric detection of extrasolar planets. Aims: We present the list of planetary transit candidates detected in the first field observed by CoRoT, IRa01, the initial run toward the Galactic anticenter, which lasted for 60 days. Methods: We
      Carpano, S. et al.

      Advertised on:

      10
      2009
      Citations
      41

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