I. Rodriguez Hidalgo

Oscillations in the Photosphere of a Sunspot Umbra from the Inversion of Infrared Stokes Profiles

We report on the detection of magnetic field strength and velocity oscillations in the photosphere of a sunspot umbra. Our analysis is based on the inversion of the full Stokes vector of three Fe I lines at 15650 A, from which the stratification with optical depth of the different atmospheric parameters has been derived. This allows us to estimate the amplitude of the oscillations and the phase lag between the fluctuations in the line-of-sight velocity and field strength. Our results suggest that the inferred magnetic field oscillations are caused by opacity fluctuations that move upward and downward the region where the spectral lines are sensitive to magnetic fields.

Stratification of the 5-min oscillation through the solar photosphere

The inversion of the radiative transfer equation has been applied to a time series of low spatial resolution Ki 7699 Å line spectra, allowing us to obtain a sequence of instantaneous models which are compared to the mean one to derive the 5-min oscillation stratification. The resulting models are reliable from log τ ≃ 0 to log τ ≃ -3.5. The increase of the velocity oscillation amplitude towards higher photospheric layers has been confirmed and quantified. Significant oscillation is observed in temperature.

Confieso que Divulgo. Reflexiones y Experiencias de una Astrofísica

Este articulo presenta algunas reflexiones en torno a la popularizacion de la Ciencia, desarrolladas a lo largo de mi trayectoria profesional, un camino inacabado desde la intuicion al oficio. Tras revisar las senas de identidad de la divulgacion cientifica, se exponen ideas, experiencias y recursos, cribados por la practica y su posterior analisis critico. Se destacan las actividades relacionadas con la Astronomia, que se cuentan entre las mas espectaculares y gratificantes. Confessions of a popularizer: This paper presents some author’s thoughts about scientific outreach, developed along her professional path, an unfinished way from intuition to trade. First, identity signs of outreach are revised; then, ideas, experiences and resources, sifted by practice and further critical analysis, are reviewed. Activities related to Astronomy, being one of the most spectacular and rewarding, are remarked 1

Quiet and Active Granulation Properties

The preliminary results of a classical spectroscopic analysis of a facular region at μ = 0.78 of ~ 100″×50″ are presented. The variation with magnetic activity of several spectroscopic parameters has been studied, showing clear evidence that granulation properties are modified.

Photometry and spectroscopy of the solar granulation along the polar axis and equator

From high-resolution CCD images of granulation obtained at the Swedish Solar Tower of the Observatorio del Roque de los Muchachos at different positions on the solar disk, mean bi-dimensional spatial power spectra have been obtained at each position and restored following the method proposed by Rodríguez Hidalgoet al. (1990). The variation with latitude of the power spectrum, of the granular brightness contrast and of the mean wave number of the power spectrum are presented. The analysis is completed with spectroscopic observations obtained at the Gregory Coudé Telescope of the Observatorio del Teide. The centre-to-limb and latitudinal variation of the bisectors, residual intensities and equivalent widths are shown for several photometric lines.