Speaker
Description
In the era of large-scale photometric surveys that achieve millimagnitude-level relative precision and have discovered thousands of exoplanets and binary systems, reassessing and improving the absolute flux scale has become essential. Accurate absolute magnitudes are critical for the detailed characterization, classification, and understanding of the formation and dynamical evolution of planetary and binary systems.
We computed synthetic TESS magnitudes for a set of high-quality spectro-photometric standard stars from the SPSS and CALSPEC libraries. The calculations were performed using both the original high-resolution library spectra and the low-resolution Gaia BP/RP mean spectra. The resulting synthetic TESS magnitudes achieve an internal precision of 0.0075 mag. A revised TESS zero point for synthetic photometry is derived, and TESS magnitudes are provided for stars in the ARIEL input catalogue.
We conclude that TESS magnitudes can be reliably determined through direct integration of Gaia BP/RP spectra — despite their incomplete wavelength coverage — reaching a significantly higher precision and improved accuracy compared to the ∼0.15 mag typical uncertainty of the TIC broad-band estimates.