Un caos magnético escondido en la galaxia del Remolino
En lo más profundo de la estructura espiral de las galaxias hay una fuerza escondida: los campos magnéticos. Pese a ser invisibles a los telescopios...
Understanding coronal rain dynamics through a point-mass model
Aims. Observations and simulations of coronal rain show that as cold and dense plasma falls through the corona, it initially undergoes acceleration by gravity...
Understanding internetwork magnetic fields as determined from visible and infrared spectral lines
We present numerical experiments aimed at understanding why near-infrared observations systematically deliver weak magnetic fields in the internetwork, whereas...
Understanding the thermal and magnetic properties of an X-class flare in the low solar atmosphere
We analyse the spatial distribution and vertical stratification of the physical parameters of the solar atmosphere when an X-class flare occurs. We made use of...
Upper chromospheric magnetic field of a sunspot penumbra: observations of fine structure
Aims: The fine-structure of the magnetic field in a sunspot penumbra in the upper chromosphere is to be explored and compared to that in the photosphere...
Upper limits from the LIGO and TAMA detectors on the rate of gravitational-wave bursts
We report on the first joint search for gravitational waves by the TAMA and LIGO collaborations. We looked for millisecond-duration unmodeled gravitational-wave...
Upper limits on gravitational wave bursts in LIGO's second science run
We perform a search for gravitational wave bursts using data from the second science run of the LIGO detectors, using a method based on a wavelet time-frequency...
Upper Limits to the Magnetic Field in Central Stars of Planetary Nebulae
More than about 20 central stars of planetary nebulae (CSPNs) have been observed spectropolarimetrically, yet no clear, unambiguous signal of the presence of a...
Variation in sunspot properties between 1999 and 2014
Aims: We study the variation in the magnetic field strength, area, and continuum intensity of umbrae in solar cycles 23 and 24. Methods: We analyzed a sample of...