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Chromospheric heights in active regions

Published online by Cambridge University Press:  14 August 2015

M.K.V. Bappu  and
K. R. Sivaraman
M.K.V. Bappu
Affiliation:
Kodaikanal Observatory, India
K. R. Sivaraman
Affiliation:
Kodaikanal Observatory, India

Abstract

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Spectra, with a radial slit in the K and Hα lines, of a sunspot close to the limb are used to determine chromospheric heights in an active region. Equidensity contours obtained with the Sabattier effect are used to measure the values of h* for different positions in the line core and wings. The spectra have also been utilized to determine similar heights in two very restricted regions of Ca+ emission which show an arched emission structure in K232 with bright continuum emission. At the K-line centre, unit tangential optical depth in the umbra, umbra-penumbra interface, and penumbra are at 1310, 1610, and 2330 km respectively. The corresponding value for the umbra in the Hα-line centre is 1080 km. The arches have a value of h = 3000 km at Δλ = 0 for the K line.

Type
Part III: Optical Structure of an Active Region
Information
Symposium - International Astronomical Union , Volume 35: Structure and Development of Solar Active Regions , 1968 , pp. 247 - 254
Copyright
Copyright © Reidel 1968 

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