학술논문
Spectroscopic investigation on two-component umbral structure
Document Type
Text
Author
Source
Publications of the Astronomical Institute of the Academy of Sciences of the Czech Republic | 1987 Volume:63-70 | Number:66
Subject
Language
Czech
Abstract
On the basis of spectroscopic observations in the lines Fe I 543.5 nm and Na I D2 the main characteristics of simple semi-empirical two-component models of 11 umbrae differing in aize (radii 2"-8") are studied. It is shovm that in large umbrae ru>4") the individual differences in brightness are mainly due to fluctuations in temperature of the dark component, while small umbrae ru<3”) differ in brightness due to the fluctuations in temperature of the dark component as well as the considerable changes in the filling factor (5% ~ 30%). The bright component is cooler than the undisturbed photosphere and in most cases it may be described by the temperature down-scaling factor Δ θ = 0.10.