Poster abstract details

Blaze residuals and their effect on the derivation of parameters of transiting planets
Matthias Ammler-von Eiff


The derivation of the properties of transiting planets depends critically on the adopted host star parameters. The determination of the latter often relies on the analysis of strong spectral lines. For example, effective temperature is usually derived from the wings of Balmer lines. The line profiles are extracted from Echelle spectra and thus can be affected by blaze residuals. The inspection of UVES spectra of OGLE-TR-10 shows that blaze residuals severely complicate the derivation of effective temperature although the residuals amount to a few percent only. They will be unnoticed in noisy spectra.
The example of the transit planet OGLE-TR-10b is presented to illustrate how uncertainties of effective temperature result in uncertainties of the derived planet parameters. Determinations of effective temperature of OGLE-TR-10 differ by hundreds of K. This is of the same order as the systematic uncertainties caused by blaze residuals in UVES spectra.
In order to correct for blaze residuals, it is essential to take spectra at sufficiently high signal-to-noise ratio. In addition, recipes of data reduction have to foresee intermediate steps to identify and remove blaze residuals.

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