Magnestismo Solar y Estelar

    General
    Descripción

    Los campos magnéticos son uno de los ingredientes fundamentales en la formación de estrellas y su evolución. En el nacimiento de una estrella, los campos magnéticos llegan a frenar su rotación durante el colapso de la nube molecular, y en el fin de la vida de una estrella, el magnetismo puede ser clave en la forma en la que se pierden las capas externas de forma dramática. En la vida adulta, el magnetismo da lugar a la actividad de las estrellas. Nuestro Sol tiene campos magnéticos que dan lugar a una actividad tan espectacular que es capaz de tener un impacto en la Tierra. Pero en otras estrellas, la actividad magnética es, en algunos casos, órdenes de magnitud más intensa que la solar, influenciando drásticamente el transporte de especies químicas y de momento angular, así como afectando posibles sistemas planetarios alrededor de éstas.

    La finalidad de este Proyecto es estudiar diversas manifestaciones del campo magnético que se pueden observar en la atmosfera solar y en otras estrellas. Estas incluyen estructuras tan diversas como las manchas solares, los campos débiles presentes en el sol en calma o estructuras cromosféricas y coronales como los filamentos y las protuberancias. Así, se han ido abordando gradualmente los siguientes temas de investigación:

     

    Magnetismo solar

    1. Estructura y evolución del campo magnético en manchas solares.
    2. Estructura y evolución del campo magnético en el Sol en calma.
    3. Estructura y evolución del campo magnético en la cromosfera y en estructuras cromosféricas (protuberancias, espículas,...)
    4. Estructura y evolución del campo magnético en bucles coronales.
    5. Estructura y evolución del campo magnético global del Sol. Estudios del ciclo de actividad magnética.
    6. Estudio empírico de la propagación de ondas magnetohidrodinámicas en el seno de estructuras magnéticas.
    7. Estudio empírico de mecanismos relacionados con el calentamiento de las capas externas del Sol.
    8. Estudio empírico de la influencia de la ionización parcial en la dinamica de la atmosfera solar.
    9. Implicación en el proyecto del Telescopio Solar Europeo.

    Magnetismo estelar

    1. Desarrollo de métodos numéricos para el diagnóstico del campo magnético estelar, tanto en la superficie como en la cromosfera.
    2. Estudio del magnetismo en protuberancias estelares.
    3. Impacto del campo magnético en las últimas fases de la evolución estelar.
    Investigador principal
    Personal del proyecto
    1. Ondas espirales en manchas solares: Se han interpretado como ondas magnetoacústicas que se propagan desde el interior hasta capas atmosféricas siguiendo la dirección del campo magnético. Se ha caracterizado la topología del campo magnético de la mancha, descartando que la forma espiral sea consecuencia del retorcimiento de las líneas de campo (Felipe et al. 2019).
    2. Respuesta magnética a umbral flashes: Observaciones espectropolarimétricas simultáneas de las líneas cromosféricas He I 10830 y Ca II 8542 fueron usadas para estimar las fluctuaciones del campo magnético asociado a ondas de choque. Los choques provocan la expansión de las líneas de campo (Houston et al. 2018, incluye a A. Asensio Ramos).

    Publicaciones relacionadas

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    • Two-fluid simulations of Rayleigh-Taylor instability in a magnetized solar prominence thread. I. Effects of prominence magnetization and mass loading

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    • Downflowing umbral flashes as evidence of standing waves in sunspot umbrae

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      1
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    • Signatures of sunspot oscillations and the case for chromospheric resonances

      Sunspots host a large variety of oscillatory phenomena, whose properties depend on the nature of the wave modes and the magnetic and thermodynamic structure of the spot. Umbral chromospheric oscillations exhibit significant differences compared to their photospheric counterparts. They show an enhanced power and a shorter dominant period, from waves

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      0
      2021
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    • Accurately constraining velocity information from spectral imaging observations using machine learning techniques

      Determining accurate plasma Doppler (line-of-sight) velocities from spectroscopic measurements is a challenging endeavour, especially when weak chromospheric absorption lines are often rapidly evolving and, hence, contain multiple spectral components in their constituent line profiles. Here, we present a novel method that employs machine learning

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      2
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    • Coronal Heating by MHD Waves

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      12
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    • Spatially resolved measurements of the solar photospheric oxygen abundance

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      11
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    • Joint action of Hall and ambipolar effects in 3D magneto-convection simulations of the quiet Sun. I. Dissipation and generation of waves

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      10
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    • Ubiquitous hundred-Gauss magnetic fields in solar spicules

      Aims: We aim to study the magnetic field in solar spicules using high-resolution spectropolarimetric observations in the Ca II 8542 Å line obtained with the Swedish 1-m Solar Telescope. Methods: The equations that result from the application of the weak field approximation (WFA) to the radiative transfer equations were used to infer the line-of

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      10
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    • The Polarimetric and Helioseismic Imager on Solar Orbiter

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    • Resonant absorption: Transformation of compressive motions into vortical motions

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      Goossens, M. et al.

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      9
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    • Chromospheric Resonances above Sunspots and Potential Seismological Applications

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      9
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    • A chromospheric resonance cavity in a sunspot mapped with seismology

      Sunspots are intense collections of magnetic fields that pierce through the Sun's photosphere, with their signatures extending upwards into the outermost extremities of the solar corona1. Cutting-edge observations and simulations are providing insights into the underlying wave generation2, configuration3,4 and damping5 mechanisms found in sunspot

      Jess, David B. et al.

      Fecha de publicación:

      1
      2020
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    • Quantifying the evidence for resonant damping of coronal waves with foot-point wave power asymmetry

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      Montes-Solís, M. et al.

      Fecha de publicación:

      8
      2020
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    • Determining the dynamics and magnetic fields in He I 10830 Å during a solar filament eruption

      Aims: We investigate the dynamics and magnetic properties of the plasma, including the line-of-sight velocity (LOS) and optical depth, as well as the vertical and horizontal magnetic fields, belonging to an erupted solar filament. Methods: The filament eruption was observed with the GREGOR Infrared Spectrograph at the 1.5-meter GREGOR telescope on

      Kuckein, C. et al.

      Fecha de publicación:

      8
      2020
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    • Numerical determination of the cutoff frequency in solar models

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      8
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    • Chromospheric Magnetic Field: A Comparison of He I 10830 Å Observations with Nonlinear Force-free Field Extrapolation

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      7
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    • On the Magnetic Nature of an Exploding Granule as Revealed by Sunrise/IMaX

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    • Numerical simulations of large-amplitude oscillations in flux rope solar prominences

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      Liakh, V. et al.

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      5
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