Start year
2000
Organizational Unit
Organizing institutions
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.
Members
Principal investigator
Savita
Mathur
Project staff
Juan Antonio
Belmonte Avilés
Hans Jörg
Deeg Deeg
Roi
Alonso Sobrino
Pere Lluís
Pallé Manzano
Fernando
Pérez Hernández
Teodoro
Roca Cortés
Savita
Mathur
Antonio
Jiménez Mancebo
Collaborators
Dr.
A. Eff-Darwich
Dr.
R. García
Dr.
Mads F. Anderson
Dr.
J. Christensen Dalsgaard
Dr.
F. Grundahl
Dr.
H. Kjeldsen
Dr.
Enrico Corsaro
Dr.
M. Cunha
Dr.
G. Davies
Dr.
T. Metcalfe
Dr.
T. Bedding
Dr.
D. Chou
Dr.
J. Fernández
Dr.
F. Hill
Dr.
S. Korzennik
Dr.
M. Deleuil
Dr.
D. Gandolfi
Dr.
M. Fridlund
Dr.
L. Doyle
Dr.
H. Rauer
Dr.
V. Kozhevnikov
Dr.
A. Hatzes
Dr.
T. Mazeh
Dr.
D. Queloz
Dr.
J. Ballot
Dr.
O. Creevey
Dr.
T. Boyajian
Results
Milestones
- 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.
- 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.
- 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).
- 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
- 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.
Scientific activity
Related publications
-
Recovering Long-term Aerosol Optical Depth Series (1976-2012) from an Astronomical Potassium-based Resonance Scattering SpectrometerA 37 year long-term series of monochromatic Aerosol Optical Depth (AOD) has been recovered from solar irradiance measurements performed with the solar spectrometer Mark-I, deployed at Izaña mountain since 1976. The instrument operation is based on the method of resonant scattering, which presents a long-term stability and high precision inBarreto, A. et al.
Advertised on:
42014 -
Re-construction of global solar radiation time series from 1933 to 2013 at the Izaña Atmospheric ObservatoryThis paper presents the re-construction of the 80 year time series of daily global shortwave downward radiation (SDR) at the subtropical high-mountain Izaña Atmospheric Observatory (IZO, Spain). For this purpose, we combine SDR estimates from sunshine duration (SD) data using the Ångström-Prescott method over the 1933/1991 period, and SDRGarcía, R. D. et al.
Advertised on:
42014 -
Seismic analysis of HD 43587Aa, a solar-like oscillator in a multiple systemContext. The object HD 43587Aa is a G0V star observed during the 145-day LRa03 run of the COnvection, ROtation and planetary Transits space mission (CoRoT), for which complementary High Accuracy Radial velocity Planet Searcher (HARPS) spectra with S/N > 300 were also obtained. Its visual magnitude is 5.71, and its effective temperature is close toBoumier, P. et al.
Advertised on:
42014 -
Seismic constraints on the radial dependence of the internal rotation profiles of six Kepler subgiants and young red giantsContext. We still do not understand which physical mechanisms are responsible for the transport of angular momentum inside stars. The recent detection of mixed modes that contain the clear signature of rotation in the spectra of Kepler subgiants and red giants gives us the opportunity to make progress on this question. Aims: Our aim is to probe theDeheuvels, S. et al.
Advertised on:
42014 -
Study of KIC 8561221 observed by Kepler: an early red giant showing depressed dipolar modesContext. The continuous high-precision photometric observations provided by the CoRoT and Kepler space missions have allowed us to understand the structure and dynamics of red giants better using asteroseismic techniques. A small fraction of these stars show dipole modes with unexpectedly low amplitudes. The reduction in amplitude is moreGarcía, R. A. et al.
Advertised on:
32014 -
Stellar Observations Network Group: The prototype is nearly readyThe prototype telescope and instruments for the Stellar Observations Network Group (SONG) are nearing completion at the Observatorio del Teide on Tenerife. In this contribution we describe the current status (autumn 2013) of the telescope and its instrumentation. Preliminary performance characteristics are presented for the high-resolutionGrundahl, F. et al.
Advertised on:
22014 -
Magnetic activity of F stars observed by KeplerContext. The study of stellar activity is important because it can provide new constraints for dynamo models when combined with surface rotation rates and the depth of the convection zone. We know that the dynamo mechanism, which is believed to be the main process that rules the magnetic cycle of solar-like stars, results from the interactionMathur, S. et al.
Advertised on:
22014 -
Transiting exoplanets from the CoRoT space mission. XXV. CoRoT-27b: a massive and dense planet on a short-period orbitAims: We report the discovery of a massive and dense transiting planet CoRoT-27b on a 3.58-day orbit around a 4.2 Gyr-old G2 star. The planet candidate was identified from the CoRoT photometry, and was confirmed as a planet with ground-based spectroscopy. Methods: The confirmation of the planet candidate is based on radial velocity observationsGandolfi, D. et al.
Advertised on:
22014 -
Kepler-91b: a planet at the end of its life. Planet and giant host star properties via light-curve variationsContext. The evolution of planetary systems is intimately linked to the evolution of their host stars. Our understanding of the whole planetary evolution process is based on the wide planet diversity observed so far. Only a few tens of planets have been discovered orbiting stars ascending the red giant branch. Although several theories have beenHenning, T. et al.
Advertised on:
22014 -
Asteroseismic Fundamental Properties of Solar-type Stars Observed by the NASA Kepler MissionWe use asteroseismic data obtained by the NASA Kepler mission to estimate the fundamental properties of more than 500 main-sequence and sub-giant stars. Data obtained during the first 10 months of Kepler science operations were used for this work, when these solar-type targets were observed for one month each in survey mode. Stellar properties haveSuran, M. D. et al.
Advertised on:
12014 -
A Full-Sun Magnetic Index from Helioseismology InferencesSolar magnetic indices are used to model the solar irradiance and ultimately to forecast it. However, the observation of such indices is generally limited to the Earth-facing hemisphere of the Sun. Seismic maps of the far side of the Sun have proven their capability to locate and track medium-large active regions at the non-visible hemisphere. WePérez-Hernández, F. et al.
Advertised on:
22014 -
An in-depth study of HD 174966 with CoRoT photometry and HARPS spectroscopy. Large separation as a new observable for δ Scuti starsAims: The aim of this work was to use a multi-approach technique to derive the most accurate values possible of the physical parameters of the δ Sct star HD 174966, which was observed with the CoRoT satellite. In addition, we searched for a periodic pattern in the frequency spectra with the goal of using it to determine the mean density of the starGarcía Hernández, A. et al.
Advertised on:
112013 -
CoRoT: Harvest of the exoplanet programOne of the objectives of the CoRoT mission is the search for transiting extrasolar planets using high-precision photometry, and the accurate characterization of their fundamental parameters. The CoRoT satellite consecutively observes crowded stellar fields since February 2007, in high-cadence precise photometry; periodic eclipses are detected andMoutou, C. et al.
Advertised on:
112013 -
Differential asteroseismic study of seismic twins observed by CoRoT. Comparison of HD 175272 with HD 181420Context. The CoRoT short asteroseismic runs give us the opportunity to observe a large variety of late-type stars through their solar-like oscillations. We report the observation and modeling of the F5V star HD 175272. Aims: Our aim is to define a method for extracting as much information as possible from a noisy oscillation spectrum. Methods: WeOzel, N. et al.
Advertised on:
102013 -
The Dynamics of the Solar Radiative ZoneThe dynamics of the solar radiative interior are still poorly constrained by comparison to the convective zone. This disparity is even more marked when we attempt to derive meaningful temporal variations. Many data sets contain a small number of modes that are sensitive to the inner layers of the Sun, but we found that the estimates of theirEff-Darwich, A. et al.
Advertised on:
102013 -
Kepler-77b: a very low albedo, Saturn-mass transiting planet around a metal-rich solar-like star⋆⋆⋆⋆⋆⋆We report the discovery of Kepler-77b (alias KOI-127.01), a Saturn-mass transiting planet in a 3.6-day orbit around a metal-rich solar-like star. We combined the publicly available Kepler photometry (quarters 1-13) with high-resolution spectroscopy from the Sandiford at McDonald and FIES at NOT spectrographs. We derived the system parameters via aGandolfi, D. et al.
Advertised on:
92013 -
High angular resolution imaging and infrared spectroscopy of CoRoT candidatesContext. Studies of transiting extrasolar planets are of key importance for understanding the nature of planets outside our solar system because their masses, diameters, and bulk densities can be measured. An important part of transit-search programmes is the removal of false-positives. In the case of the CoRoT space mission, the majority of theGuenther, E. W. et al.
Advertised on:
82013 -
Atmospheric parameters of 169 F-, G-, K- and M-type stars in the Kepler fieldThe asteroseismic and planetary studies, like all research related to stars, need precise and accurate stellar atmospheric parameters as input. We aim at deriving the effective temperature (Teff), the surface gravity (log g), the metallicity ([Fe/H]), the projected rotational velocity (v sin i) and the MK type for 169 F-, G-, K- and M-type KeplerMolenda-Żakowicz, J. et al.
Advertised on:
92013 -
Transiting exoplanets from the CoRoT space mission. XXIV. CoRoT-25b and CoRoT-26b: two low-density giant planetsWe report the discovery of two transiting exoplanets, CoRoT-25b and CoRoT-26b, both of low density, one of which is in the Saturn mass-regime. For each star, ground-based complementary observations through optical photometry and radial velocity measurements secured the planetary nature of the transiting body and allowed us to fully characterizeAlmenara, J. M. et al.
Advertised on:
72013 -
The unusual roAp star KIC 8677585KIC 8677585 is a roAp star in the Kepler field which is unique in that there are four low-frequency variations of unknown origin in addition to more than 20 high-frequency roAp modes. We analysed all available spectroscopy and conclude that the star has a constant radial velocity and most likely not a binary. We estimate its effective temperatureBalona, L. A. et al.
Advertised on:
72013
