title: Searching and Characterising Exoplanets using Astrometry and Doppler Spectroscopy
creator: Schulze-Hartung, Tim
subject: ddc-520
subject: 520 Astronomy and allied sciences
description: The discovery of exoplanets plays a key role both in advancing theoretical models and in the search for extraterrestrial life. Most planet candidates have so far been detected by means of Doppler spectroscopy of their central star. The radial velocities thus measured, in combination with astrometry, allow to draw conclusions on the mass and orbital characteristics of the accompanying object. In this work, models which theoretically describe the corresponding observables are derived.  Under the assumption of an error model, these observable models can be compared to the measured data. Here, the Bayesian approach is detailed and pursued as a statistical method. In addition to considering a priori knowledge, it allows to derive probability densities over the parameters as well as the statistically robust detection of exoplanets.  To apply the Bayesian method to astrometric and radial-velocity data, the computer program BASE has been significantly extended. After presenting the tool in detail, it is employed to determine the orbit of the binary star Mizar A. This leads to a confirmation of earlier results and well-founded statements on the parameter uncertainties.  For the nearby star epsilon Eridani, a frequency analysis and the Bayes factor do not support unanimous conclusions about the presence of a controversial planetary companion. This might be caused by stellar activity and properties of the underlying data. Further investigation of these effects seems promising.
date: 2012
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/14440/1/Dissertation_TSH_hyperref.pdf
identifier: DOI:10.11588/heidok.00014440
identifier: urn:nbn:de:bsz:16-heidok-144403
identifier:   Schulze-Hartung, Tim  (2012) Searching and Characterising Exoplanets using Astrometry and Doppler Spectroscopy.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/14440/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng