Leiden University Scholarly Publications

On excitation and maintenance of secondary oscillations in pulsating stars

On an asymptotic relation between the variations of luminosity and radius in the theory of Cepheid variables

On the theory of anadiabatic star pulsations: a continuation, extended and emended

On the possibility of excitation of a long-period secondary oscillation in ζ Geminorum

On the anomalous phase relation between first and second harmonic in the radial velocity of ζ Geminorum and related stars

Note on the light-variation of Cepheid variables with secondary period

On the critical values of the amplitudes required to maintain the pulsation of Cepheid variation

On the theory of non-adiabatic star pulsations

On the diffusion of monochromatic radiation through a medium consisting of plan-parallel layers in relative motion

Note on the circular vortex in the theory of sunspots

Note on the energy equation

The resistance experienced by the outward moving chromospheric Ca<SUP>+</SUP> ions and its effect on the density

The structure of the Ca<SUP>+</SUP> chromosphere and the observations of the K line

The Ca<SUP>+</SUP> chromosphere

Note on the contour of the H-K emission line of the chromosphere

On the theory of the chromosphere and the corona

Note on the excitation of "forbidden" lines in the nebular spectrum

Line absorption and Cepheid pulsation

Additional note on the continuous spectrum of the corona

On the continuous spectrum of the corona

Line absorption and absorption coefficient inside a star

On the possibility of a gravitational shift of the spectral lines of O and B stars

On the energy required for the ionization of the interior of a star

On the stationary Calcium lines