Observations of the calcium coronal lines in the vicinity of a limb flare.

Abstract

view Abstract Citations References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Observations of the calcium coronal lines in the vicinity of a limb flare. Zirin, Harold Abstract Since the X4o86 coronal line has been identified as due to CaxIli in the laboratory, we have attempted to compare it with the yellow line, X5694, to check its identification as Caxv. These lines were observed almost simultaneously, in the vicinity of an importance-two limb flare on December 18, 1956. The time variation of both lines parallels that of the flare. The Doppler half- widths of X4086 and X5694 are equivalent; both correspond to a temperature of 10,000,0000, if the broadening is purely thermal. Unless the line broadening is ascribed completely to micro- turbulence, the conclusion is inescapable that ~4086 and X5694 are both due to highly ionized states of calcium, and therefore X5694 is probably due to Caxv. Twenty-six emission lines are observed in the flare spectrum between X3888 and ~4I43. These include lines of H, He, FeI, CaII, All, MnI, MgI, Till and Srii. Comparison of the HeI and Till profiles yields a kinetic temperature around 200,0000. This work was carried out under the sponsorship of Air Force Cambridge Research Center. High Altitude Observatory, Boulder, Colo. Publication: The Astronomical Journal Pub Date: July 1957 DOI: 10.1086/107504 Bibcode: 1957AJ.....62..149Z full text sources ADS |