Search Publications

Kinematic analysis of stellar radial velocities by the spherical harmonics

Tsvetkov, A. S.; Vityazev, V. V.; Trofimov, D. A.

A method for a kinematic analysis of stellar radial velocities using spherical harmonics is proposed. This approach does not depend on the specific kinematic model and allows both low-frequency and high-frequency kinematic radial velocity components to be analyzed. The possible systematic variations of distances with coordinates on the celestial s…

Distortion of the stellar velocity field parameters due to systematic variations of parallaxes over the celestial sphere

Tsvetkov, A. S.; Vityazev, V. V.

We study the effect of systematic variations in stellar parallaxes over the celestial sphere on the results of a kinematic analysis of stellar proper motions. Our approach is based on the representation of stellar parallaxes by scalar spherical harmonics and on the decomposition of stellar proper motions into a system of vector spherical harmonics…

Method of ignoring the systematic variations of stellar parallaxes over the celestial sphere in a kinematic analysis of stellar proper motions

Tsvetkov, A. S.; Vityazev, V. V.

A method for determining the velocity field parameters free from the distortions due to the systematic variations of stellar parallaxes over the celestial sphere is proposed. The method is based on the approximation of parallaxes as a function of coordinates on the sphere using spherical harmonics and can be applied in those cases where the solar …