Geometry of irradiated stars

A. C. Wawrzyn, H. M. Gunther, T. S. Barman, P. H. Hauschildt

Research output: Contribution to journalConference articlepeer-review


The physical conditions in a variety of objects (e.g. hot exoplanets and close binaries) are fundamentally influenced by external irradiation. In static cases this leads to the development of zones of different temperatures on the 'day-side'. In order to combine spectra from all zones to a full visible circular disk and to obtain a 1.5D spectrum we need to calculate the weight of each patch. In the following we present the geometrical considerations and calculate the observed projected area of constant temperature in an irradiated object for specific re-radiation angles. This allows non-isotropic models to be used. We supply an IDL code to calculate the observed projected area for any patch given the phase and angle between surface and line of sight as well as a proper weighting for each by numerical integration. We end up with a simple approach to upgrade a ID irradiation model to a quasi 1.5D one. This method can be applied e.g. to irradiated secondaries in close binaries.

Original languageEnglish (US)
Pages (from-to)973-976
Number of pages4
JournalAIP Conference Proceedings
StatePublished - 2009
Event15th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun - St. Andrews, United Kingdom
Duration: Jul 21 2008Jul 25 2008


  • Close - binaries
  • Eclipsing
  • Methods
  • Miscellaneous - binaries
  • Numerical - techniques

ASJC Scopus subject areas

  • General Physics and Astronomy


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