Año de inicio
1999
Unidad organizativa
Institución organizadora
Subvenciones relacionadas:
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
- Estructura y evolución del campo magnético en manchas solares.
- Estructura y evolución del campo magnético en el Sol en calma.
- Estructura y evolución del campo magnético en la cromosfera y en estructuras cromosféricas (protuberancias, espículas,...)
- Estructura y evolución del campo magnético en bucles coronales.
- Estructura y evolución del campo magnético global del Sol. Estudios del ciclo de actividad magnética.
- Estudio empírico de la propagación de ondas magnetohidrodinámicas en el seno de estructuras magnéticas.
- Estudio empírico de mecanismos relacionados con el calentamiento de las capas externas del Sol.
- Estudio empírico de la influencia de la ionización parcial en la dinamica de la atmosfera solar.
- Implicación en el proyecto del Telescopio Solar Europeo.
Magnetismo estelar
- Desarrollo de métodos numéricos para el diagnóstico del campo magnético estelar, tanto en la superficie como en la cromosfera.
- Estudio del magnetismo en protuberancias estelares.
- Impacto del campo magnético en las últimas fases de la evolución estelar.
Miembros
Investigador principal
Tobías
Felipe García
Personal del proyecto
Elena
Khomenko Shchukina
Íñigo
Arregui Uribe-Echevarría
Andrés
Asensio Ramos
Carlos Humberto
Domínguez-Tagle Paredes
María Jesús
Martínez González
Juan Carlos
Trelles Arjona
Carlos
Westendorp Plaza
Colaboradores
Héctor David
Socas Navarro
Dr.
J.C. del Toro Iniesta
Dr.
R. Kostik
Dr.
N. Shchukina
Dr.
V. Olshevsky
Dr.
A. Sainz Dalda
Dr.
W. Schmidt
Dr.
Th. Berkefeld
Dr.
S.K. Solanki
Dr.
A. Gandorfer
Prof.
P. Cally
Dr.
S. Shelyag
Dr.
M. Stangalini
Dr.
C. Beck
Dr.
C. Kuckein
Dr.
C. Quintero Noda
Dr.
I. Calvo Santamaria
Dr.
C. González Fernández
Dr.
J.de la Cruz Rodríguez
Dr.
M. Leitzinger
Dr.
A. Pastor Yabar
Dr.
A. López Ariste
Dr.
Franco Leone
Dr.
R. Manso Sainz
Dr.
Luis R Bellot Rubio
Resultados
- 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).
- 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).
Actividad científica
Publicaciones relacionadas
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Helioseismic holography of simulated sunspots: dependence of the travel time on magnetic field strength and Wilson depressionImproving methods for determining the subsurface structure of sunspots from their seismic signature requires a better understanding of the interaction of waves with magnetic field concentrations. We aim to quantify the impact of changes in the internal structure of sunspots on local helioseismic signals. We have numerically simulated theFelipe, T. et al.
Fecha de publicación:
82017 -
Zeeman effect in sulfur monoxide. A tool to probe magnetic fields in star forming regionsContext. Magnetic fields play a fundamental role in star formation processes and the best method to evaluate their intensity is to measure the Zeeman effect of atomic and molecular lines. However, a direct measurement of the Zeeman spectral pattern from interstellar molecular species is challenging due to the high sensitivity and high spectralCazzoli, G. et al.
Fecha de publicación:
92017 -
Comparison of Damping Mechanisms for Transverse Waves in Solar Coronal LoopsWe present a method to assess the plausibility of alternative mechanisms to explain the damping of magnetohydrodynamic transverse waves in solar coronal loops. The considered mechanisms are resonant absorption of kink waves in the Alfvén continuum, phase mixing of Alfvén waves, and wave leakage. Our methods make use of Bayesian inference and modelMontes-Solís, M. et al.
Fecha de publicación:
92017 -
Chromospheric polarimetry through multiline observations of the 850-nm spectral region - II. A magnetic flux tube scenarioIn this publication, we continue the work started in Quintero Noda et al., examining this time a numerical simulation of a magnetic flux tube concentration. Our goal is to study if the physical phenomena that take place in it, in particular, the magnetic pumping, leaves a specific imprint on the examined spectral lines. We find that the profilesSuematsu, Y. et al.
Fecha de publicación:
112017 -
Solar polarimetry through the K I lines at 770 nmWe characterize the K I D1 & D2 lines in order to determine whether they could complement the 850 nm window, containing the Ca II infrared triplet lines and several Zeeman sensitive photospheric lines, that was studied previously. We investigate the effect of partial redistribution on the intensity profiles, their sensitivity to changes inSuematsu, Y. et al.
Fecha de publicación:
92017 -
Discovery of Scattering Polarization in the Hydrogen Lyα Line of the Solar Disk RadiationThere is a thin transition region (TR) in the solar atmosphere where the temperature rises from 10,000 K in the chromosphere to millions of degrees in the corona. Little is known about the mechanisms that dominate this enigmatic region other than the magnetic field plays a key role. The magnetism of the TR can only be detected by polarimetricKano, R. et al.
Fecha de publicación:
42017 -
Penumbral thermal structure below the visible surfaceContext. The thermal structure of the penumbra below its visible surface (i.e., τ5 ≥ 1) has important implications for our present understanding of sunspots and their penumbrae: their brightness and energy transport, mode conversion of magneto-acoustic waves, sunspot seismology, and so forth. Aims: We aim at determining the thermal stratificationBorrero, J. M. et al.
Fecha de publicación:
52017 -
Indication of the Hanle Effect by Comparing the Scattering Polarization Observed by CLASP in the Lyα and Si iii 120.65 nm LinesThe Chromospheric Lyman-Alpha Spectro-Polarimeter is a sounding rocket experiment that has provided the first successful measurement of the linear polarization produced by scattering processes in the hydrogen Lyα line (121.57 nm) radiation of the solar disk. In this paper, we report that the Si iii line at 120.65 nm also shows scatteringIshikawa, R. et al.
Fecha de publicación:
52017 -
The dusty tori of nearby QSOs as constrained by high-resolution mid-IR observationsWe present mid-infrared (MIR; 7.5-13.5 μm) imaging and spectroscopy observations obtained with the CanariCam (CC) instrument on the 10.4-m Gran Telescopio CANARIAS for a sample of 20 nearby, MIR bright and X-ray luminous quasi-stellar objects (QSOs). We find that for the majority of QSOs the MIR emission is unresolved at angular scales ∼0.3 arcsecMartínez-Paredes, M. et al.
Fecha de publicación:
62017 -
Uncertainties in the solar photospheric oxygen abundanceAims: The purpose of this work is to better understand the confidence limits of the photospheric solar oxygen abundance derived from three-dimensional models using the forbidden [OI] line at 6300 Å, including correlations with other parameters involved. Methods: We worked with a three-dimensional empirical model and two solar intensity atlasesCubas Armas, M. et al.
Fecha de publicación:
32017 -
Spectropolarimetric Evidence for a Siphon Flow along an Emerging Magnetic Flux TubeWe study the dynamics and topology of an emerging magnetic flux concentration using high spatial resolution spectropolarimetric data acquired with the Imaging Magnetograph eXperiment on board the sunrise balloon-borne solar observatory. We obtain the full vector magnetic field and the line of sight (LOS) velocity through inversions of the Fe i lineRequerey, I. S. et al.
Fecha de publicación:
32017 -
Polarization Calibration of the Chromospheric Lyman-Alpha SpectroPolarimeter for a 0.1% Polarization Sensitivity in the VUV Range. Part II: In-Flight CalibrationThe Chromospheric Lyman-Alpha SpectroPolarimeter is a sounding rocket instrument designed to measure for the first time the linear polarization of the hydrogen Lyman-{α} line (121.6 nm). The instrument was successfully launched on 3 September 2015 and observations were conducted at the solar disc center and close to the limb during the five-minutesGiono, G. et al.
Fecha de publicación:
42017 -
Inference of the chromospheric magnetic field orientation in the Ca ii 8542 Å line fibrilsContext. Solar chromospheric fibrils, as observed in the core of strong chromospheric spectral lines, extend from photospheric field concentrations suggesting that they trace magnetic field lines. These images have been historically used as proxies of magnetic fields for many purposes. Aims: Use statistical analysis to test whether the associationAsensio Ramos, A. et al.
Fecha de publicación:
32017 -
Dependence of sunspot photospheric waves on the depth of the source of solar p-modesPhotospheric waves in sunspots moving radially outward at speeds faster than the characteristic wave velocities have been recently detected. It has been suggested that they are the visual pattern of p-modes excited around 5 Mm beneath the sunspot's surface. Using numerical simulations, we performed a parametric study of the waves observed at theFelipe, T. et al.
Fecha de publicación:
22017 -
Observations of Ellerman bomb emission features in He i D3 and He i 10 830 ÅContext. Ellerman bombs (EBs) are short-lived emission features, characterised by extended wing emission in hydrogen Balmer lines. Until now, no distinct signature of EBs has been found in the He i 10 830 Å line, and conclusive observations of EBs in He i D3 have never been reported. Aims: We aim to study the signature of EBs in neutral heliumLibbrecht, T. et al.
Fecha de publicación:
12017 -
Synthetic polarimetric spectra from stellar prominencesStellar prominences detected in rapidly rotating stars serve as probes of the magnetism in the corona of cool stars. We have synthesized the temporal evolution of the Stokes profiles generated in the He I 10 830 and 5876 Å triplets during the rotation of a prominence around a star. The synthesis was performed with the HAZEL code using a cloud modelFelipe, T. et al.
Fecha de publicación:
22017 -
How to infer the Sun's global magnetic field using the Hanle effectWe present a different approach to determine the characteristics of the global magnetic field of the Sun based on the study of the Hanle signals. The Hanle effect of a stellar dipole produces a surface asymmetric pattern of linear polarization that depends on the strength and geometry of this global field. Moreover, if the dipole is misaligned withVieu, T. et al.
Fecha de publicación:
32017 -
Gyro-viscosity and linear dispersion relations in pair-ion magnetized plasmasA fluid theory has been developed by taking account of gyro-viscosity to study wave propagation characteristics in a homogeneous pair-ion magnetized plasma with a cylindrical symmetry. The exact dispersion relations derived by the Hankel-Fourier transformation are shown comparable with those observed in the experiment by Oohara and co-workers. TheKono, M. et al.
Fecha de publicación:
112015 -
Oscillations and Waves in SunspotsA magnetic field modifies the properties of waves in a complex way. Significant advances have been made recently in our understanding of the physics of sunspot waves with the help of high-resolution observations, analytical theories, as well as numerical simulations. We review the current ideas in the field, providing the most coherent picture ofKhomenko, E. et al.
Fecha de publicación:
112015 -
Evershed flow observed in neutral and singly ionized iron linesThe amplitudes of the Evershed flow are measured using pairs of carefully selected Fe i and Fe ii spectral lines that are close in wavelength and registered simultaneously. A sunspot belonging to the NOAA 11582 group was scanned using the spectrograph of the German Vacuum Tower Telescope (Observatorio del Teide, Tenerife). Velocities were extractedKhomenko, E. et al.
Fecha de publicación:
122015
