General
Los objetivos genéricos de este Proyecto son: 1) el estudio de la estructura y dinámica del interior solar, 2) la extensión de dicho estudio al caso de otras estrellas, 3) la búsqueda y caracterización de planetas extrasolares por métodos fotométricos (principalmente mediante el método de tránsitos) y espectroscópico (variaciones en la velocidad radial de la estrella) y 4) el análisis de las atmósferas de estos planetas.
Para el primer objetivo se utiliza la heliosismología tanto global (la que se obtiene de los modos propios de oscilación) como la local (que deriva del estudio de ondas viajeras). La sismología solar permite inferir de modo preciso información acerca de la estructura y dinámicas internas del Sol. El presente proyecto cubre las distintas facetas necesarias para alcanzar dicho objetivo, desde la instrumental, pasando por la observacional, técnicas de reducción, análisis e interpretación de los datos, así como el desarrollo de técnicas teóricas de inversión y elaboración de modelos de estructura y evolución.
Por otro lado, la astrosismología pretende obtener un conocimiento similar en otras estrellas. Hoy en día esta rama de la astrofísica está produciendo un gran número de resultados gracias a la enorme cantidad de estrellas observadas por las misiones espaciales CoRoT, Kepler y TESS, siendo posible extraer información sobre la estructura y dinámica de cientos de estrellas, tanto de tipo solar como de gigantes rojas. Todo ello se verá complementado con el desarrollo de la red SONG (Stellar Observations Network Group), una batería de telescopio en Tierra dotados con espectrógrafos.
La estrategia de utilización de tránsitos planetarios para descubrir la existencia de planetas alrededor de otras estrellas, consiste en la detección fotométrica de disminuciones de brillo de una estrella cuando uno de sus planetas está pasando entre ella y el observador. Actualmente esta metodología es la preferida para la investigación de planetas pequeños, no sólo por su sensibilidad sino también porque permite llevar a cabo estudios relativamente detallados de los planetas descubiertos. Esta tecnología es similar a la que se utiliza en helio y astrosismología por lo que se puede entender como una extensión lógica de lo aprendido con los anteriores objetivos. Por otro lado, es importante desarrollar algoritmos y métodos observacionales para la detección inequívoca y el análisis de los planetas, distinguiéndolos de los que resultan ser falsas alarmas.
El panorama actual para los estudios de exoplanetas involucra nuevas misiones espaciales como CHEOPS y TESS que serán seguidos por JWST y en 2026, PLATO. Por lo tanto, se abre una ventana temporal en la que los observatorios terrestres pueden complementar estos datos. Para ello seguimos llevando a cabo observaciones usando principalmente TNG, NOT, GTC.
Members
Results
- Miembros del grupo (P. G. Beck, H. Deeg, S. Mathur, F. Pérez, C. Régulo) estuvieron involucrados en el descubrimiento y caracterización de un "Saturno caliente" que hospeda la estrella HD 89345 observada con la misión K2 y confirmada con medidas de VR. El análisis sísmico permitió obtener estimaciones precisas de los parámetros estelares.
- P.G.Beck dirigió dos artículos sobre binarias con gigantes rojas, usando técnicas astrosimológicas para mejorar la comprensión de su estructura y efectos de marea. También se estudio la mezcla de material en su interior midiendo abundancias de Litio.
- S. Mathur participó en el análisis del primer planeta descubierto por la misión TESS, que orbita la estrella Pi Men. El análisis sísmico condujo a una detección marginal pero dió una pista del potencial uso de la astrosismología con TESS (Gandolfi et al. 2018).
- Proyecto "Solar-SONG". Por vez primera se ha utilizado instrumentación estelar (espectrógrafo SONG) para obtener medidas precisas de la velocidad radial del Sol con alta cadencia temporal (4 s.) y duración suficiente (57 días consecutivos) como para permitir el estudio detallado del espectro de oscilaciones (modos-p) y obtener sus parámetros globales
- Los investigadores Hans J. Deeg y Juan Antonio Belmonte coordinaron la edición del libro "Handbook of Exoplanets" con 160 artículos y la participación de más de 300 especialistas. Tres años de trabajo resultaron en una colección completa y actualizada del estudio de los planetas más allá del sistema solar.
Scientific activity
Publicaciones relacionadas
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Noise properties of the CoRoT data. A planet-finding perspectiveIn this short paper, we study the photometric precision of stellar light curves obtained by the CoRoT satellite in its planet-finding channel, with a particular emphasis on the time scales characteristic of planetary transits. Together with other articles in the same issue of this journal, it forms an attempt to provide the building blocks for aAigrain, S. et al.
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102009 -
Ground-based photometry of space-based transit detections: photometric follow-up of the CoRoT missionThe motivation, techniques and performance of the ground-based photometric follow-up of transit detections by the CoRoT space mission are presented. Its principal raison d'être arises from the much higher spatial resolution of common ground-based telescopes in comparison to CoRoT's cameras. This allows the identification of many transit candidatesDeeg, H. J. et al.
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102009 -
Ground-based Near-infrared Observations of the Secondary Eclipse of CoRoT-2bWe present the results of a ground-based search for the secondary eclipse of the 3.3 M Jup transiting planet CoRoT-2b. We performed near-infrared photometry using the LIRIS instrument on the 4.2 m William Herschel Telescope, in the H and Ks filters. We monitored the star around two expected secondary eclipses in two nights under very good observingAlonso, R. et al.
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42010 -
Extrasolar planet detection by binary stellar eclipse timing: evidence for a third body around CM DraconisAims:Our objective is to elucidate the physical process that causes the observed observed-minus-calculated (O-C) behavior in the M4.5/M4.5 binary CM Dra and to test for any evidence of a third body around the CM Dra system. Methods: New eclipse minimum timings of CM Dra were obtained between the years 2000 and 2007. The O-C times of the system areDeeg, H. J. et al.
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32008 -
Exoplanet discoveries with the CoRoT space observatoryThe CoRoT space observatory is a project which is led by the French space agency CNES and leading space research institutes in Austria, Brazil, Belgium, Germany and Spain and also the European Space Agency ESA. CoRoT observed since its launch in December 27, 2006 about 100 000 stars for the exoplanet channel, during 150 days uninterrupted highLammer, H. et al.
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122010 -
Exo-Dat: An Information System in Support of the CoRoT/Exoplanet ScienceExo-Dat is a database and an information system created primarily in support of the exoplanet program of the COnvection ROtation & planetary Transits (CoRoT) mission. In the directions of CoRoT pointings, it provides a united interface to several sets of data: stellar published catalogs, photometric and spectroscopic data obtained during theDeleuil, M. et al.
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82009 -
CoRoT LRa02_E2_0121: Neptune-size planet candidate turns into a hierarchical triple system with a giant primaryThis paper presents the case of CoRoT LRa02_E2_0121, which was initially classified as a Neptune-size transiting-planet candidate on a relatively wide orbit of 36.3 days. Follow-up observations were performed with UVES, Sandiford, SOPHIE, and HARPS. These observations revealed a faint companion in the spectra. To find the true nature of the systemTal-Or, L. et al.
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102011 -
A transiting giant planet with a temperature between 250K and 430KOf the over 400 known exoplanets, there are about 70 planets that transit their central star, a situation that permits the derivation of their basic parameters and facilitates investigations of their atmospheres. Some short-period planets, including the first terrestrial exoplanet (CoRoT-7b), have been discovered using a space mission designed toDeeg, H. J. et al.
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32010 -
CoRoT Measures Solar-Like Oscillations and Granulation in Stars Hotter Than the SunOscillations of the Sun have been used to understand its interior structure. The extension of similar studies to more distant stars has raised many difficulties despite the strong efforts of the international community over the past decades. The CoRoT (Convection Rotation and Planetary Transits) satellite, launched in December 2006, has nowMichel, Eric et al.
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102008 -
Preliminary results on the contribution of the convection motions to the Doppler velocity signalThis investigation aims to study the correlation of the solar background with atmosphere. We used high resolution observations of the NaDl spectral line. In fact the large span in formation heights of this spectral line allowed us to infer the signal from photosphere to chromosphere. We analyzed the data by applying the SIR code (Stokes InversionSimoniello, R. et al.
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102008 -
Infrared astronomical characteristics of the Roque de los Muchachos Observatory: precipitable water vapour statisticsWe present measurements of the atmospheric water vapour content above the Roque de los Muchachos Observatory (ORM) obtained using the Global Positioning System (GPS). The GPS measurements have been evaluated by comparison with 940-nm radiometer observations. A statistical analysis of the GPS measurements points to the ORM as an observing site withGarcía-Lorenzo, B. et al.
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72010 -
Ground-based Multisite Observations of Two Transits of HD 80606bWe present ground-based optical observations of the 2009 September and 2010 January transits of HD 80606b. Based on three partial light curves of the 2009 September event, we derive a midtransit time of Tc [HJD] = 2455099.196 ± 0.026, which is about 1σ away from the previously predicted time. We observed the 2010 January event from nine differentShporer, A. et al.
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102010 -
Limits to the planet candidate GJ 436cWe report on H-band, ground-based observations of a transit of the hot Neptune GJ 436b. Once combined to achieve sampling equivalent to archived observations taken with Spitzer, our measurements reach comparable precision levels. We analyze both sets of observations in a consistent way, and measure the rate of orbital inclination change to be of 0Alonso, R. et al.
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82008 -
TrES-5: A Massive Jupiter-sized Planet Transiting a Cool G DwarfWe report the discovery of TrES-5, a massive hot Jupiter that transits the star GSC 03949-00967 every 1.48 days. From spectroscopy of the star we estimate a stellar effective temperature of T eff = 5171 ± 36 K, and from high-precision B, R, and I photometry of the transit we constrain the ratio of the semimajor axis a and the stellar radius RMandushev, Georgi et al.
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112011 -
Transit timing analysis of the exoplanets TrES-1 and TrES-2Aims. The aim of this work is a detailed analysis of transit light curves from TrES-1 and TrES-2, obtained over a period of three to four years, in order to search for variabilities in observed mid-transit times and to set constraints on the presence of additional third bodies. Methods: Using the IAC 80 cm telescope, we observed transits of TrES-1Rabus, M. et al.
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122009 -
SYMPA, a dedicated instrument for Jovian seismology. II. Real performance and first resultsAims: SYMPA is the first instrument dedicated to the observation of free oscillations of Jupiter. Its principles and theoretical performance have been presented in Paper I. This second paper describes the data processing method, the real instrumental performance and presents the first results of a Jovian observation run, lead in 2005 at TeideGaulme, P. et al.
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112008 -
Detection of transit timing variations in excess of one hour in the Kepler multi-planet candidate system KOI 806 with the GTCAims: We report the detection of transit timing variations (TTVs) well in excess of one hour in the Kepler multi-planet candidate system KOI 806. This system exhibits transits consistent with three separate planets - a Super-Earth, a Jupiter, and a Saturn - lying very nearly in a 1:2:5 resonance, respectively. Methods: We used the Kepler publicTingley, B. et al.
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122011 -
Constraints of a pulsation frequency on stellar parameters in the eclipsing spectroscopic binary system V577 OphWe present a preliminary spectroscopic analysis of the binary system V577Oph, observed during the summer of 2007 on the 2.6 m NOT telescope on La Palma. We have obtained time series spectroscopic observations, which show clear binary motion as well as radial velocity variations due to pulsation in the primary star. By modelling the radialCreevey, O. L. et al.
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122010 -
Constraining the Properties of Delta Scuti Stars Using Spectroscopic Eclipsing Binary SystemsMany stars exhibit stellar pulsations, favoring them for asteroseismic analyses. Interpreting the oscillations requires some knowledge of the oscillation mode geometry (spherical degree, radial, and azimuthal orders). The δ Scuti stars (1.5-2.5 M sun) often show just one or few pulsation frequencies. Although this may promise a successfulCreevey, O. L. et al.
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52011 -
An eclipsing post-common-envelope binary in the field of the Kepler missionWe present a new eclipsing post-common-envelope binary, identified inside the Kepler field prior to the launch of the spacecraft. Multifilter photometry and radial velocity data are analysed with an eclipsing-binary modelling code to determine the physical parameters of the binary. Spectra of the system within the primary eclipse and uneclipsedAlmenara, J. M. et al.
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32012