A new source of opacity in stellar atmospheres.

Abstract

view Abstract Citations (1) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A new source of opacity in stellar atmospheres. Varsavsky, Carlos M. Abstract Limb-darkening observations between N3700 and X6700 obtained by Peyturaux in 1953 are analyzed by expanding the source function in terms of the exponential integrals introduced by Kourganoff. From the calculated values of the derivative of the optical depth with respect to temperature and the accepted values of the absorption coefficient of H-, it is deduced that some unknown source of opacity is of importance at wave lengths less than X5ooo and temperatures lower than 65000, confirming previous reports of other authors. While analyzing several sources of opacity it was found that a transition between the unstable (Is~) (2~~)1~a+ level of the H2 molecule and its (Is~) (2s~)1~0+ level produces a very significant absorption in the far ultraviolet. Quantitative calculations of the amount of absorption and its wave-length dependence are made, and the conclusion is reached that this process provides the major source of opacity between X1600 and X2600. It does not, however, explain the increased absorption observed in the blue and near ultraviolet spectrum. Harvard College Observatory, Cambridge, Mass. Publication: The Astronomical Journal Pub Date: May 1957 DOI: 10.1086/107473 Bibcode: 1957AJ.....62...97V full text sources ADS |