Estrellas de Baja Masa, Enanas Marrones y Planetas

    General
    Descripción

    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.

    1. 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
    2. El limite estelar/subestelar del cumulo más cercano al Sol, las Hiades

    Publicaciones relacionadas

    • The CARMENES search for exoplanets around M dwarfs. Telluric absorption corrected high S/N optical and near-infrared template spectra of 382 M dwarf stars

      Light from celestial objects interacts with the molecules of the Earth's atmosphere, resulting in the production of telluric absorption lines in ground-based spectral data. Correcting for these lines, which strongly affect red and infrared wavelengths, is often needed in a wide variety of scientific applications. Here, we present the template

      Nagel, E. et al.

      Fecha de publicación:

      12
      2023
      Número de citas
      3
    • TOI-1801 b: A temperate mini-Neptune around a young M0.5 dwarf

      We report the discovery, mass, and radius determination of TOI-1801 b, a temperate mini-Neptune around a young M dwarf. TOI-1801 b was observed in TESS sectors 22 and 49, and the alert that this was a TESS planet candidate with a period of 21.3 days went out in April 2020. However, ground-based follow-up observations, including seeing-limited

      Goffo, E. et al.

      Fecha de publicación:

      12
      2023
      Número de citas
      0
    • Planetary companions orbiting the M dwarfs GJ 724 and GJ 3988. A CARMENES and IRD collaboration

      We report the discovery of two exoplanets around the M dwarfs GJ 724 and GJ 3988 using the radial velocity (RV) method. We obtained a total of 153 3.5 m Calar Alto/CARMENES spectra for both targets and measured their RVs and activity indicators. We also added archival ESO/HARPS data for GJ 724 and infrared RV measurements from Subaru/IRD for GJ

      Gorrini, P. et al.

      Fecha de publicación:

      12
      2023
      Número de citas
      0
    • Photometric follow-up of the 20 Myr old multi-planet host star V1298 Tau with CHEOPS and ground-based telescopes

      Context. The 20 Myr old star V1298 Tau hosts at least four planets. Since its discovery, this system has been a target of intensive photometric and spectroscopic monitoring. To date, the characterisation of its architecture and planets' fundamental properties has been very challenging. Aims: The determination of the orbital ephemeris of the

      Damasso, M. et al.

      Fecha de publicación:

      12
      2023
      Número de citas
      1
    • The GAPS programme at TNG. XLVIII. The unusual formation history of V1298 Tau

      Context. Observational data from space- and ground-based campaigns have revealed that the 10-30 Ma old V1298Tau star hosts a compact and massive system of four planets. Mass estimates are available for the two outer giant planets and point to unexpectedly high densities for their young ages. Aims: We investigate the formation of these two outermost

      Turrini, D. et al.

      Fecha de publicación:

      11
      2023
      Número de citas
      2
    • A compact multi-planet system transiting HIP 29442 (TOI-469) discovered by TESS and ESPRESSO. Radial velocities lead to the detection of transits with low signal-to-noise ratio

      Context. One of the goals of the Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations (ESPRESSO) Guaranteed Time Observations (GTO) consortium is the precise characterisation of a selected sample of planetary systems discovered by TESS. One such target is the K0V star HIP 29442 (TOI-469), already known to host a validated

      Damasso, M. et al.

      Fecha de publicación:

      11
      2023
      Número de citas
      0
    • Optical properties of metal-poor T dwarf candidates

      Context. Metal-poor brown dwarfs are poorly understood because they are extremely faint and rare. Only a few candidates have been identified as T-type subdwarfs in infrared surveys and their optical properties remain unconstrained. Aims: We aim to improve the knowledge of the optical properties of T subdwarf candidates to break the degeneracy

      Zhang, J. -Y. et al.

      Fecha de publicación:

      10
      2023
      Número de citas
      1
    • Young nearby open clusters and their luminosity functions

      Context. Open clusters are groups of coeval stars sharing properties such as distance and metallicity, and they are key to understanding stellar evolution. Aims: Our main goal is to study the evolution of open clusters with a special focus on the universality of the luminosity function. Methods: We applied an upgraded version of the convergent

      Žerjal, M. et al.

      Fecha de publicación:

      10
      2023
      Número de citas
      0
    • GJ 806 (TOI-4481): A bright nearby multi-planetary system with a transiting hot low-density super-Earth

      One of the main scientific goals of the TESS mission is the discovery of transiting small planets around the closest and brightest stars in the sky. Here, using data from the CARMENES, MAROON-X, and HIRES spectrographs together with TESS, we report the discovery and mass determination of aplanetary system around the M1.5 V star GJ 806 (TOI-4481)

      Palle, E. et al.

      Fecha de publicación:

      10
      2023
      Número de citas
      3
    • The CARMENES search for exoplanets around M dwarfs. Behaviour of the Paschen lines during flares and quiescence

      The hydrogen Paschen lines are known activity indicators, but studies of them in M dwarfs during quiescence are as rare as their reports in flare studies. This situation is mostly caused by a lack of observations, owing to their location in the near-infrared regime, which is covered by few high-resolution spectrographs. We study the Paβ line, using

      Fuhrmeister, B. et al.

      Fecha de publicación:

      10
      2023
      Número de citas
      2
    • Two super-Earths at the edge of the habitable zone of the nearby M dwarf TOI-2095

      The main scientific goal of TESS is to find planets smaller than Neptune around stars that are bright enough to allow for further characterization studies. Given our current instrumentation and detection biases, M dwarfs are prime targets in the search for small planets that are in (or near) the habitable zone of their host star. In this work, we

      Murgas, F. et al.

      Fecha de publicación:

      9
      2023
      Número de citas
      3
    • Modeling the Chromosphere and Transition Region of Planet-hosting Star GJ 436

      Ahead of upcoming space missions intending to conduct observations of low-mass stars in the ultraviolet (UV) spectral region it becomes imperative to simultaneously conduct atmospheric modeling from the UV to the visible (VIS) and near-infrared (NIR). Investigations on extended spectral regions will help to improve the overall understanding of the

      Hintz, Dominik et al.

      Fecha de publicación:

      9
      2023
      Número de citas
      1
    • TOI-1130: A photodynamical analysis of a hot Jupiter in resonance with an inner low-mass planet

      The 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 our

      Korth, J. et al.

      Fecha de publicación:

      7
      2023
      Número de citas
      2
    • Two sub-Neptunes around the M dwarf TOI-1470

      Aims: A transiting planet candidate with a sub-Neptune radius orbiting the nearby (d = 51.9 ± 0.07 pc) M1.5 V star TOI-1470 with a period of ~2.5 d was announced by the NASA Transiting Exoplanet Survey Satellite (TESS), which observed the field of TOI-1470 in four different sectors. We aim to validate its planetary nature using precise radial

      González-Álvarez, E. et al.

      Fecha de publicación:

      7
      2023
      Número de citas
      0
    • The CARMENES search for exoplanets around M dwarfs. A sub-Neptunian mass planet in the habitable zone of HN Lib

      We report the discovery of HN Lib b, a sub-Neptunian mass planet orbiting the nearby (d ≈ = 6.25 pc) M4.0 V star HN Lib detected by our CARMENES radial-velocity (RV) survey. We determined a planetary minimum mass of Mb sin i = 5.46 ± 0.75 M⊕ and an orbital period of Pb = 36.116 ± 0.029 d, using ~5 yr of CARMENES data, as well as archival RVs from

      González-Álvarez, E. et al.

      Fecha de publicación:

      7
      2023
      Número de citas
      0
    • An unusually low-density super-Earth transiting the bright early-type M-dwarf GJ 1018 (TOI-244)

      Context. Small planets located at the lower mode of the bimodal radius distribution are generally assumed to be composed of iron and silicates in a proportion similar to that of the Earth. However, recent discoveries are revealing a new group of low-density planets that are inconsistent with that description. Aims: We intend to confirm and

      Castro-González, A. et al.

      Fecha de publicación:

      7
      2023
      Número de citas
      4
    • The cosmic waltz of Coma Berenices and Latyshev 2 (Group X). Membership, phase-space structure, mass, and energy distributions

      Context. Open clusters (OCs) are fundamental benchmarks where theories of star formation and stellar evolution can be tested and validated. Coma Berenices (Coma Ber) and Latyshev 2 (Group X) are the second and third OCs closest to the Sun, making them excellent targets to search for low-mass stars and ultra-cool dwarfs. In addition, this pair will

      Olivares, J. et al.

      Fecha de publicación:

      7
      2023
      Número de citas
      1
    • The CARMENES search for exoplanets around M dwarfs. Line-by-line sensitivity to activity in M dwarfs

      Context. Radial velocities (RVs) measured from high-resolution stellar spectra are routinely used to detect and characterise orbiting exoplanet companions. The different lines present in stellar spectra are created by several species, which are non-uniformly affected by stellar variability features such as spots or faculae. Stellar variability

      Lafarga, M. et al.

      Fecha de publicación:

      6
      2023
      Número de citas
      3
    • New constraints on the presence of debris disks around G 196-3 B and VHS J125601.92-125723.9 b

      Context. The existence of warm (protoplanetary) disks around very young isolated planetary and brown dwarf mass objects is known based on near- and mid-infrared flux excesses and millimeter observations. These disks may later evolve into debris disks or rings, although none have been observed or confirmed so far. Little is known about circum(sub

      Zakhozhay, Olga V. et al.

      Fecha de publicación:

      6
      2023
      Número de citas
      0
    • The CARMENES search for exoplanets around M dwarfs. A deep transfer learning method to determine T<SUB>eff</SUB> and [M/H] of target stars

      The large amounts of astrophysical data being provided by existing and future instrumentation require efficient and fast analysis tools. Transfer learning is a new technique promising higher accuracy in the derived data products, with information from one domain being transferred to improve the accuracy of a neural network model in another domain

      Bello-García, A. et al.

      Fecha de publicación:

      5
      2023
      Número de citas
      0

    Charlas relacionadas

    No se han encontrado charlas relacionadas.

    Congresos relacionados

    No se han encontrado congresos relacionados.