Multi-Wavelength Eclipse Observations of a Quiescent Prominence

• Published in: Solar physics Vol. 289; no. 7; pp. 2487 - 2501
• Main Authors: Jejčič, S., Heinzel, P., Zapiór, M., Druckmüller, M., Gunár, S., Kotrč, P.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.07.2014; Springer Nature B.V
• Subjects: Astrophysics and Astroparticles; Atmospheric Sciences; Construction; Electron density; Gas pressure; Mathematical models; Physics; Physics and Astronomy; Prominences; Solar eclipses; Solar physics; Solar radiation; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Spatial analysis; Spectral emissivity; Wave power; Mongolia; Prominences, quiescent; Spectral line, intensity and diagnostics; Eclipse observations
• ISSN: 0038-0938; 1573-093X
• DOI: 10.1007/s11207-014-0482-1

We construct the maps of temperatures, geometrical thicknesses, electron densities and gas pressures in a quiescent prominence. For this we use the RGB signal of the prominence visible-light emission detected during the total solar eclipse of 1 August 2008 in Mongolia and quasi-simultaneous Hα spectra taken at Ondřejov Observatory. The method of disentangling the electron density and geometrical (effective) thickness was described by Jejčič and Heinzel ( Solar Phys. 254 , 89 – 100, 2009 ) and is used here for the first time to analyse the spatial variations of prominence parameters. For the studied prominence we obtained the following range of parameters: temperature 6000 – 15 000 K, effective thickness 200 – 15000 km, electron density 5×10 9  – 10 11 cm −3 and gas pressure 0.02 – 0.2 dyn cm −2 (assuming a fixed ionisation degree n p / n H =0.5). The electron density increases towards the bottom of the prominence, which we explain by an enhanced photoionisation due to the incident solar radiation. To confirm this, we construct a two-dimensional radiative-transfer model with realistic prominence illumination.