Subvenciones relacionadas:
General
Se investigan los procesos que conducen a la formación de estrellas de baja masa, enanas marrones y exoplanetas y caracterizar las propiedades físicas de estos astros en varias etapas evolutivas. Las estrellas de muy baja masa y las enanas marrones son probablemente los objetos más numerosos de nuestra Galaxia, pero no por ello están suficientemente bien establecidas sus propiedades. En particular, los objetos subestelares constituyen uno de los grupos más difíciles de estudiar desde el punto de vista observacional dada su baja luminosidad intrínseca. Se pretende establecer la frecuencia, multiplicidad y distribución espacial de estrellas ultrafrías y objetos subestelares en la vecindad del Sol y en regiones de formación estelar y cúmulos cercanos con el fin de proporcionar información sobre los mecanismos que los originan, caracterizar sus propiedades ópticas e infrarrojas, y establecer relaciones entre sus propiedades espectrales, masas y luminosidades. Se hace especial énfasis en empujar la frontera de detección hacia los objetos de menor masa, bien sea como objetos ligados por atracción gravitatoria a otros, o flotando libremente en el espacio interestelar. Los objetos menos masivos también suelen ser los de menor luminosidad intrínseca y temperaturas superficiales más frías por lo que entrañan notable dificultad de detección por medio de imagen directa. Sin embargo, la detección directa permite una caracterización fotométrica y espectroscópica mucho más completa y una mejor determinación de sus propiedades físicas y químicas. También se pretende investigar la presencia de exoplanetas en estrellas de baja masa empleando técnicas de medida de velocidad radial con muy alta precisión y técnicas de muy alta resolución espacial. Se trabaja en el desarrollo de espectrógrafos ultraestables para grandes telescopios y de sistemas de imagen ultrarrápida. Con los primeros es posible lograr la detección de planetas con masas similares a la de la Tierra en estrellas de tipos G, K y M un objetivo que se persigue es establecer la frecuencia de estos planetas en las estrellas de la vecindad solar y caracterizar las propiedades de los sistemas planetarios a los que pertenecen.
Miembros
Resultados
- La secuencia visible y infrarroja de las enanas de tipo L de 10 Myr de edad en la asociación OB mas cercana al Sol, Upper Scorpius
- El limite estelar/subestelar del cumulo más cercano al Sol, las Hiades
Actividad científica
Publicaciones relacionadas
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CARMENES input catalogue of M dwarfs: VIII. Kinematics in the solar neighbourhoodAims. Our goals are to characterise the kinematic properties and to identify young and old stars among the M dwarfs of the CARMENES input catalogue. Methods. We compiled the spectral types, proper motions, distances, and radial velocities for 2187 M dwarfs. We used the public code SteParKin to derive their galactic space velocities and identifyCortés-Contreras, M. et al.
Fecha de publicación:
122024 -
Characterisation of TOI-406 as a showcase of the THIRSTEE program: A two-planet system straddling the M-dwarf density gapContext. The exoplanet sub-Neptune population currently poses a conundrum, as to whether small-size planets are volatile-rich cores without an atmosphere, or rocky cores surrounded by a H-He envelope. To test the different hypotheses from an observational point of view, a large sample of small-size planets with precise mass and radius measurementsLacedelli, G. et al.
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122024 -
The CARMENES search for exoplanets around M dwarfs: The impact of rotation and magnetic fields on the radial velocity jitter in cool starsContext. Radial velocity (RV) jitter represents an intrinsic limitation on the precision of Doppler searches for exoplanets that can originate from both instrumental and astrophysical sources. Aims. We aim to determine the RV jitter floor in M dwarfs and investigate the stellar properties that lead to RV jitter induced by stellar activity. MethodsRuh, H. L. et al.
Fecha de publicación:
122024 -
Coronal and chromospheric activity of Teegarden's starTeegarden's star is a late-type M-dwarf planet host, typically showing only rather low levels of activity. In this paper we present an extensive characterisation of this activity at photospheric, chromospheric, and coronal levels. We specifically investigated TESS observations of Teegarden's star, which showed two very large flares with anFuhrmeister, B. et al.
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112024 -
Hints of auroral and magnetospheric polarized radio emission from the scallop-shell star 2MASS J05082729–2101444Scallop-shell stars, a recently discovered class of young M dwarfs, show complex optical light curves that are characterized by periodic dips as well as other features that are stable over tens to hundreds of rotation cycles. The origin of these features is not well-understood. 2MASS J05082729‑2101444 is a ∼25 Myr old scallop-shell star that wasKaur, Simranpreet et al.
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112024 -
The obliquity and atmosphere of the hot Jupiter WASP-122b (KELT-14b) with ESPRESSO: An aligned orbit and no sign of atomic or molecular absorptionThanks to their short orbital periods and hot extended atmospheres, hot Jupiters are ideal candidates for atmosphere studies with high- resolution spectroscopy. New stable spectrographs help improve our understanding of the evolution and composition of those types of planets. By analyzing two nights of observations using the ESPRESSO highStangret, M. et al.
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112024 -
The GAPS Programme at TNG: LIX. Characterisation study of the ∼300 Myr-old multi-planetary system orbiting the star BD+40 2790 (TOI-2076)Context. The long-term Global Architecture of Planetary Systems (GAPS) programme has been characterising a sample of young systems with transiting planets via spectroscopic and photometric follow-up observations. One of the main goals of GAPS is measuring planets' dynamical masses and bulk densities to help build a picture of how planets evolve inPedani, M. et al.
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102024 -
A sub-Earth-mass planet orbiting Barnard's starContext. ESPRESSO guaranteed time observations (GTOs) at the 8.2m VLT telescope were performed to look for Earth-like exoplanets in the habitable zone of nearby stars. Barnard's star is a primary target within the ESPRESSO GTO as it is the second closest neighbour to our Sun after the α Centauri stellar system. Aims. We present here a large set ofGonzález Hernández, J. I. et al.
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102024 -
Validation of up to seven TESS planet candidates through multi-colour transit photometry using MuSCAT2 dataThe TESS mission searches for transiting exoplanets by monitoring the brightness of hundreds of thousands of stars across the entire sky. M-type planet hosts are ideal targets for this mission due to their smaller size and cooler temperatures, which makes it easier to detect smaller planets near or within their habitable zones. Additionally, MPeláez-Torres, A. et al.
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102024 -
The CARMENES search for exoplanets around M dwarfs: Magnesium and silicon abundances of K7–M5.5 starsWe present the abundances of magnesium (Mg) and silicon (Si) for 314 dwarf stars with spectral types in the interval K7.0–M5.5 (T eff range ≈ 4200–3050 K) observed with the CARMENES high-resolution spectrograph at the 3.5 m telescope at the Calar Alto Observatory. Our analysis employs the BT-Settl model atmospheres, the radiative transfer codeTabernero, H. M. et al.
Fecha de publicación:
92024 -
Revisiting the dynamical masses of the transiting planets in the young AU Mic system: Potential AU Mic b inflation at 20 MyrContext. Understanding planet formation is important in the context of the origin of planetary systems in general and of the Solar System in particular, as well as to predict the likelihood of finding Jupiter, Neptune, and Earth analogues around other stars. Aims. We aim to precisely determine the radii and dynamical masses of transiting planetsMallorquín, M. et al.
Fecha de publicación:
92024 -
The atmospheric composition of the ultra-hot Jupiter WASP-178 b observed with ESPRESSOContext. Ultra-hot Jupiters (UHJ) have emerged as ideal testbeds for new techniques for studying exoplanet atmospheres. Only a limited number of them are currently well studied, however. Aims. We search for atmospheric constituents for the UHJ WASP-178 b with two ESPRESSO transits. Additionally, we show parallel photometry that we used to obtainDamasceno, Y. C. et al.
Fecha de publicación:
92024 -
ESPRESSO reveals blueshifted neutral iron emission lines on the dayside of WASP-76 bContext. Ultra hot Jupiters (gas giants with T eq > 2000 K) are intriguing exoplanets due to the extreme physics and chemistry present in their atmospheres. Their torrid daysides can be characterised using ground-based high-resolution emission spectroscopy. Aims. We search for signatures of neutral and singly ionised iron (Fe I and Fe IICosta Silva, A. R. et al.
Fecha de publicación:
92024 -
Three super-Earths and a possible water world from TESS and ESPRESSOContext. Since 2018, the ESPRESSO spectrograph at the VLT has been hunting for planets in the southern skies via the radial velocity (RV) method. One of its goals is to follow up on candidate planets from transit surveys such as the TESS mission, with a particular focus on small planets for which ESPRESSO's RV precision is vital. Aims: We aim toHobson, M. J. et al.
Fecha de publicación:
82024 -
The CARMENES search for exoplanets around M dwarfs. Revisiting the GJ 581 multi-planetary system with new Doppler measurements from CARMENES, HARPS, and HIRESContext. GJ 581 is a nearby M dwarf known to host a packed multiple planet system composed of two super-Earths and a Neptune-mass planet. We present new orbital analyses of the GJ 581 system, utilizing recent radial velocity (RV) data obtained from the CARMENES spectrograph combined with newly reprocessed archival data from the HARPS and HIRESvon Stauffenberg, A. et al.
Fecha de publicación:
82024 -
Detection of an Earth-sized exoplanet orbiting the nearby ultracool dwarf star SPECULOOS-3Located at the bottom of the main sequence, ultracool dwarf stars are widespread in the solar neighbourhood. Nevertheless, their extremely low luminosity has left their planetary population largely unexplored, and only one of them, TRAPPIST-1, has so far been found to host a transiting planetary system. In this context, we present the SPECULOOSGillon, Michaël et al.
Fecha de publicación:
72024 -
TOI-837 b is a young Saturn-sized exoplanet with a massive 70 M<SUB>⊕</SUB> coreWe present an exhaustive photometric and spectroscopic analysis of TOI-837, a F9/G0 35 Myr young star, hosting a transiting exoplanet, TOI-837 b, with an orbital period of ~8.32 d. Utilizing data from the Transiting Exoplanet Survey Satellite and ground-based observations, we determine a planetary radius of $0.818_{-0.024}^{+0.034}$ R J for TOI-837Barragán, Oscar et al.
Fecha de publicación:
72024 -
The Discovery and Follow-up of Four Transiting Short-period Sub-Neptunes Orbiting M DwarfsSub-Neptunes with radii of 2–3 R ⊕ are intermediate in size between rocky planets and Neptune-sized planets. The orbital properties and bulk compositions of transiting sub-Neptunes provide clues to the formation and evolution of close-in small planets. In this paper, we present the discovery and follow-up of four sub-Neptunes orbiting M dwarfs (TOIHori, Yasunori et al.
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62024 -
TOI-4438 b: a transiting mini-Neptune amenable to atmospheric characterizationWe report the confirmation and mass determination of a mini-Neptune transiting the M3.5 V star TOI-4438 (G 182-34) every 7.44 days. A transit signal was detected with NASA's TESS space mission in the sectors 40, 52, and 53. In order to validate the planet TOI-4438 b and to determine the system properties, we combined TESS data with high-precisionGoffo, E. et al.
Fecha de publicación:
52024 -
Gliese 12 b: A Temperate Earth-sized Planet at 12 pc Ideal for Atmospheric Transmission SpectroscopyRecent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the atmospheres of terrestrial planets via follow-up spectroscopic observations. However, the number of such planets receiving low insolation is still small, limiting our ability to understand the diversity of the atmospheric composition andKuzuhara, Masayuki et al.
Fecha de publicación:
62024