Poznań Spectroscopy Project

Spectra yield great wealth of information on stellar motions, structure and evolution of stars. Variable stars are interesting per se but also because they constitute cosmic milestones for measurement of cosmic distances. For many nearby stars accurate distances were/will be obtained by trigonometric method from Hipparchos and GAIA satellites. To measure larger distances observations of many types of variable stars can be used. Photometric and spectroscopic studies of such objects allow determination of their physical parameters, one of them being the surface brightness. By comparing it to the measured flux one can easily derive the distance to the star.

One of the important parts of the variable star method is its calibration on nearby stars, for which accurate distances have been obtained with the purely geometrical method. However, for large telescopes nearby stars are often too bright and instrument time is too precious to observe them. At the same time the available data on these bright stars are often sparse or of low quality.

Here comes a project like ours handy: we already build a modern and efficient echelle spectrograph and will use it with a small but fully automatic telescope for high quality spectroscopic observations of nearby variable stars with accurate trigonometric distances. The telescope is being constructed by our team right now. At the beginning it will be placed at Borowiec Observatory in Poland with an option to transport it to a better site in the future. The spectrograph and telescope designs are by J. Baudrand and R. Baranowski, respectively.

Our team

Our group at the moment consists of Tomasz Kwiatkowski (leader), Roman Baranowski (designer & engineer), Alex Schwarzenberg-Czerny (science program), Przemyslaw Bartczak (control software) and Wojciech Dimitrov (data reduction).

Echelle spectrograph

Binary telescope

Scientific program

  • Eclipsing binary stars
  • Pulsating stars