Rigorous treatment of barycentric stellar motion Perspective and lighttime effects in astrometric and radial velocity data
(2014) In Astronomy & Astrophysics 570. Abstract
 Context. Highprecision astrometric and radialvelocity observations require accurate modelling of stellar motions in order to extrapolate measurements over long time intervals, and to detect deviations from uniform motion caused, for example, by unseen companions. Aims. We aim to explore the simplest possible kinematic model of stellar motions, namely that of uniform rectilinear motion relative to the solar system barycentre, in terms of observable quantities including error propagation. Methods. The apparent path equation for uniform rectilinear motion is solved analytically in a classical (specialrelativistic) framework, leading to rigorous expressions that relate the (apparent) astrometric parameters and radial velocity to the (true)... (More)
 Context. Highprecision astrometric and radialvelocity observations require accurate modelling of stellar motions in order to extrapolate measurements over long time intervals, and to detect deviations from uniform motion caused, for example, by unseen companions. Aims. We aim to explore the simplest possible kinematic model of stellar motions, namely that of uniform rectilinear motion relative to the solar system barycentre, in terms of observable quantities including error propagation. Methods. The apparent path equation for uniform rectilinear motion is solved analytically in a classical (specialrelativistic) framework, leading to rigorous expressions that relate the (apparent) astrometric parameters and radial velocity to the (true) kinematic parameters of the star in the barycentric reference system. Results. We present rigorous and explicit formulae for the transformation of stellar positions, parallaxes, proper motions, and radial velocities from one epoch to another, assuming uniform rectilinear motion and taking lighttime effects into account. The Jacobian matrix of the transformation is also given, allowing accurate and reversible propagation of errors over arbitrary time intervals. The lighttime effects are generally very small, but exceed 0.1 mas or 0.1 m s(1) over 100 yr for at least 33 stars in the Hipparcos catalogue. For highvelocity stars within a few tens of pc from the Sun, lighttime effects are generally more important than the effects of the curvature of their orbits in the Galactic potential. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/4875696
 author
 Butkevich, A. G. and Lindegren, Lennart ^{LU}
 organization
 publishing date
 2014
 type
 Contribution to journal
 publication status
 published
 subject
 keywords
 methods: data analysis, technique: radial velocity, astrometry, parallaxes, proper motions, reference systems
 in
 Astronomy & Astrophysics
 volume
 570
 article number
 A62
 publisher
 EDP Sciences
 external identifiers

 wos:000344158500120
 scopus:84907966246
 ISSN
 00046361
 DOI
 10.1051/00046361/201424483
 language
 English
 LU publication?
 yes
 id
 432486a7d6074b06a1dc028bc1d46716 (old id 4875696)
 date added to LUP
 20160401 13:38:59
 date last changed
 20210929 02:21:11
@article{432486a7d6074b06a1dc028bc1d46716, abstract = {Context. Highprecision astrometric and radialvelocity observations require accurate modelling of stellar motions in order to extrapolate measurements over long time intervals, and to detect deviations from uniform motion caused, for example, by unseen companions. Aims. We aim to explore the simplest possible kinematic model of stellar motions, namely that of uniform rectilinear motion relative to the solar system barycentre, in terms of observable quantities including error propagation. Methods. The apparent path equation for uniform rectilinear motion is solved analytically in a classical (specialrelativistic) framework, leading to rigorous expressions that relate the (apparent) astrometric parameters and radial velocity to the (true) kinematic parameters of the star in the barycentric reference system. Results. We present rigorous and explicit formulae for the transformation of stellar positions, parallaxes, proper motions, and radial velocities from one epoch to another, assuming uniform rectilinear motion and taking lighttime effects into account. The Jacobian matrix of the transformation is also given, allowing accurate and reversible propagation of errors over arbitrary time intervals. The lighttime effects are generally very small, but exceed 0.1 mas or 0.1 m s(1) over 100 yr for at least 33 stars in the Hipparcos catalogue. For highvelocity stars within a few tens of pc from the Sun, lighttime effects are generally more important than the effects of the curvature of their orbits in the Galactic potential.}, author = {Butkevich, A. G. and Lindegren, Lennart}, issn = {00046361}, language = {eng}, publisher = {EDP Sciences}, series = {Astronomy & Astrophysics}, title = {Rigorous treatment of barycentric stellar motion Perspective and lighttime effects in astrometric and radial velocity data}, url = {http://dx.doi.org/10.1051/00046361/201424483}, doi = {10.1051/00046361/201424483}, volume = {570}, year = {2014}, }