Found 3 talks width keyword polarimeters

Tuesday June 8, 2021

Mapping the Sun's upper photosphere with artificial neural networks

IAC

Abstract

In this talk I'll present results from a recent paper in which we have developed a new analysis technique for solar spectra based on artificial neural networks. Our first test applications yielded some unexpected and interesting results. The fine-scale network of temperature enhancements in the quiet middle and upper photosphere have a reversed pattern. Hot pixels in the middle photosphere, possibly associated with small-scale magnetic elements, appear cool at higher levels (log(tau)=-3 and -4), and vice versa. We also find hot arcs on the limb side of magnetic pores, which we interpret as the first direct observational evidence of the "hot wall" effect. Hot walls are a prediction of theoretical models from the 1970s which had not been observed until now.

Archived in: Stars - Keywords:Machine learning, atomic processes, magnetic fields, quantum mechanics, radiative transfer, scattering, stellar dynamics, turbulence, stars spots, stellar activity, Hinode, polarimeters, spectrographs, solar granulation, solar magnetic fields, solar photosphere, sunspots

Abstract

Friday April 9, 2021

El software de Gris. Presente y futuro.

IAC

Abstract

En la presente charla hablaremos de la sobre la actualización que se está llevando a cabo en el software de control del Instrumento Gris de Gregor y como se ha intentado poner en marcha un sistema de integración continua. Además, se comentará la idea de montar un banco polar basado en un sistema de integración continua.

Archived in: Telescopes and instrumentation - Keywords:software, polarimeters

Abstract

Monday June 13, 2011

Imaging polarimetry of circumstellar environments. Science Results of ExPo

Astronomical Institute Utrecht, the Netherlands

Abstract

ExPo is an imaging polarimeter that has been built in Utrecht University. ExPo works in the visible, and it combines the dual-beam technique, together with very short exposure times and a high polarization sensitivity. After four successful campaigns at the William Herschel Telescope, we have obtained polarization images of circumstellar environments around T Tau's and Herbig Ae's stars, evolved (post-AGB) stars and planets like Venus and Saturn. Our results prove the utility of imaging polarimetry to characterize faint structures around very different objects. In this talk I will go through the instrument details, and I will show some of our science results.

Archived in: Telescopes and instrumentation, Stars - Keywords:polarimetry, polarimeters, circumstellar matter, AGB and post-AGB

Abstract

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