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
-
No random transits in CHEOPS observations of HD 139139Context. The star HD 139139 (a.k.a. `the Random Transiter') is a star that exhibited enigmatic transit-like features with no apparent periodicity in K2 data. The shallow depth of the events (~200 ppm - equivalent to transiting objects with radii of ~1.5 R ⊕ in front of a Sun-like star) and their non-periodicity constitute a challenge for theAlonso, R. et al.
Advertised on:
122023 -
In search of gravity mode signatures in main sequence solar-type stars observed by KeplerGravity modes (g modes), mixed gravito-acoustic modes (mixed modes), and gravito-inertial modes (gi modes) possess unmatched properties as probes for stars with radiative interiors. The structural and dynamical constraints that they are able to provide cannot be accessed by other means. While they provide precious insights into the internalBreton, S. N. et al.
Advertised on:
112023 -
Stellar spectral-type (mass) dependence of the dearth of close-in planets around fast-rotating stars. Architecture of Kepler confirmed single-exoplanet systems compared to star-planet evolution modelsIn 2013 a dearth of close-in planets around fast-rotating host stars was found using statistical tests on Kepler data. The addition of more Kepler and Transiting Exoplanet Survey Satellite (TESS) systems in 2022 filled this region of the diagram of stellar rotation period (P rot) versus the planet orbital period (P orb). We revisited the P rotGarcía, R. A. et al.
Advertised on:
112023 -
A resonant sextuplet of sub-Neptunes transiting the bright star HD 110067Planets with radii between that of the Earth and Neptune (hereafter referred to as `sub-Neptunes') are found in close-in orbits around more than half of all Sun-like stars 1,2. However, their composition, formation and evolution remain poorly understood 3. The study of multiplanetary systems offers an opportunity to investigate the outcomes ofWinn, J. N. et al.
Advertised on:
112023 -
CHEOPS and TESS view of the ultra-short-period super-Earth TOI-561 bContext. Ultra-short-period planets (USPs) are a unique class of super-Earths with an orbital period of less than a day, and hence they are subject to intense radiation from their host star. These planets cannot retain a primordial H/He atmosphere, and most of them are indeed consistent with being bare rocky cores. A few USPs, however, showPatel, J. A. et al.
Advertised on:
112023 -
Refining the properties of the TOI-178 system with CHEOPS and TESSContext. The TOI-178 system consists of a nearby late K-dwarf transited by six planets in the super-Earth to mini-Neptune regime, with radii ranging from ~1.1 to 2.9 R ⊕ and orbital periods between 1.9 and 20.7 days. All planets but the innermost one form a chain of Laplace resonances. Mass estimates derived from a preliminary radial velocity (RV)Delrez, L. et al.
Advertised on:
102023 -
Asteroseismology and Spectropolarimetry of the Exoplanet Host Star λ SerpentisThe bright star λ Ser hosts a hot Neptune with a minimum mass of 13.6 M ⊕ and a 15.5 day orbit. It also appears to be a solar analog, with a mean rotation period of 25.8 days and surface differential rotation very similar to the Sun. We aim to characterize the fundamental properties of this system and constrain the evolutionary pathway that led toMetcalfe, Travis S. et al.
Advertised on:
102023 -
A 5M<SUB>Jup</SUB> non-transiting coplanar circumbinary planet around Kepler-1660ABOver a dozen transiting circumbinary planets have been discovered around eclipsing binaries. Transit detections are biased towards aligned planet and binary orbits, and indeed all of the known planets have mutual inclinations less than 4.5 ○. One path to discovering circumbinary planets with misaligned orbits is through eclipse timing variationsGoldberg, Max et al.
Advertised on:
112023 -
Investigating the visible phase-curve variability of 55 Cnc e★Context. 55 Cnc e is an ultra-short period super-Earth transiting a Sun-like star. Previous observations in the optical range detected a time-variable flux modulation that is phased with the planetary orbital period, whose amplitude is too large to be explained by reflected light and thermal emission alone. Aims: The goal of the study is toMeier Valdés, E. A. et al.
Advertised on:
92023 -
Company for the Ultra-high Density, Ultra-short Period Sub-Earth GJ 367 b: Discovery of Two Additional Low-mass Planets at 11.5 and 34 DaysGJ 367 is a bright (V ≈ 10.2) M1 V star that has been recently found to host a transiting ultra-short period sub-Earth on a 7.7 hr orbit. With the aim of improving the planetary mass and radius and unveiling the inner architecture of the system, we performed an intensive radial velocity follow-up campaign with the HARPS spectrograph-collecting 371Goffo, Elisa et al.
Advertised on:
92023 -
TOI-2084 b and TOI-4184 b: Two new sub-Neptunes around M dwarf starsWe present the discovery and validation of two TESS exoplanets orbiting nearby M dwarfs: TOI-2084 b, and TOI-4184b. We characterized the host stars by combining spectra from Shane/Kast and Magellan/FIRE, spectral energy distribution analysis, and stellar evolutionary models. In addition, we used Gemini-South/Zorro & -North/Alopeke high-resolutionBarkaoui, K. et al.
Advertised on:
92023 -
TOI-1416: A system with a super-Earth planet with a 1.07 d periodTOI-1416 (BD+42 2504, HIP 70705) is a V =10 late G- or early K-type dwarf star. TESS detected transits in its Sectors 16, 23, and 50 with a depth of about 455 ppm and a period of 1.07 days. Radial velocities (RVs) confirm the presence of the transiting planet TOI-1416 b, which has a mass of 3.48 ± 0.47 M ⊕ and a radius of 1.62 ± 0.08 R ⊕, implyingDeeg, H. J. et al.
Advertised on:
92023 -
Everything that glitters is not gold: V1315 Cas is not a dormant black holeThe quest for quiet or dormant black holes has been ongoing since several decades. Ellipsoidal variables possibly indicate the existence of a very high-mass invisible companion and are thought to be one of the best ways to find such dormant black holes. This, however, is not a panacea as we show here with one example. We indeed report the discoveryZak, J. et al.
Advertised on:
102023 -
TOI-1130: A photodynamical analysis of a hot Jupiter in resonance with an inner low-mass planetThe TOI-1130 is a known planetary system around a K-dwarf consisting of a gas giant planet, TOI-1130 c on an 8.4-day orbit that is accompanied by an inner Neptune-sized planet, TOI-1130 b, with an orbital period of 4.1 days. We collected precise radial velocity (RV) measurements of TOI-1130 with the HARPS and PFS spectrographs as part of ourKorth, J. et al.
Advertised on:
72023 -
Unresolved Rossby and gravity modes in 214 A and F stars showing rotational modulationHere, we report an ensemble study of 214 A- and F-type stars observed by Kepler, exhibiting the so-called hump and spike periodic signal, explained by Rossby modes (r modes) - the hump - and magnetic stellar spots or overstable convective (OsC) modes - the spike, respectively. We determine the power confined in the non-resolved hump features andHenriksen, Andreea I. et al.
Advertised on:
92023 -
Magnetic Activity Evolution of Solar-like Stars. I. S <SUB>ph</SUB>-Age Relation Derived from Kepler ObservationsThe ages of solar-like stars have been at the center of many studies such as exoplanet characterization or Galactic-archeology. While ages are usually computed from stellar evolution models, relations linking ages to other stellar properties, such as rotation and magnetic activity, have been investigated. With the large catalog of 55,232 rotationMathur, Savita et al.
Advertised on:
82023 -
The planetary system around HD 190622 (TOI-1054). Measuring the gas content of low-mass planets orbiting F-starsContext. Giant planets are known to dominate the long-term stability of planetary systems due to their prevailing gravitational interactions, but they are also thought to play an important role in planet formation. Observational constraints improve our understanding of planetary formation processes such as the delivery of volatile-richCabrera, J. et al.
Advertised on:
72023 -
Solar-like oscillations in γ Cephei A as seen through SONG and TESS. A seismic study of γ Cephei AContext. Fundamental stellar parameters such as mass and radius are some of the most important building blocks in astronomy, both when it comes to understanding the star itself and when deriving the properties of any exoplanet(s) they may host. Asteroseismology of solar-like oscillations allows us to determine these parameters with high precisionKnudstrup, E. et al.
Advertised on:
72023 -
FX UMa: A New Heartbeat Binary System with Linear and Nonlinear Tidal Oscillations and δ Sct PulsationsWe present a detailed analysis of an eclipsing double-lined binary FX UMa based on TESS photometry and newly acquired spectroscopic observations. The radial velocities and atmospheric parameters for each component star are obtained from the SONG high-resolution spectra. Combined with the radial-velocity measurements, our light-curve modeling yieldsWang, Kun et al.
Advertised on:
82023 -
The breakdown of current gyrochronology as evidenced by old coeval starsGyrochronology can yield useful ages for field main-sequence stars, a regime where other techniques are problematic. Typically, gyrochronology relations are calibrated using young (≲2 Gyr) clusters, but the constraints at older ages are scarce, making them potentially inaccurate and imprecise. In order to test the performance of existing relationsSilva-Beyer, Joaquín et al.
Advertised on:
82023
