Gaia DR1 known issues - Gaia
Known issues with the Gaia DR1 data
This page lists the issues in our first data release that have been discovered after the release of the Gaia data and related documentation. The Gaia DR1 contents page contains a summary of limitations that were known, and documented, already at the release date. Tips on how to better make use of the Gaia Archive can be found here.
Overview:
Variability: Documentation of definition of Fourier decomposition of G-band light curve in Gaia DR1 and Gaia DR2
The variability processing coordination unit in the Gaia Data Processing and Analysis Consortium (CU7 in the Gaia DPAC) is responsible for the processing and classification of variable stars. Their software used for Cepheid and RR Lyrae variables is based on a Fourier decomposition of the broad-band G-band light curve and derives the Fourier parameters φ21, φ31, R21, and R31 using a (truncated) Fourier expansion in cosine functions. This definition has been used for Gaia DR1, Gaia DR2, and Gaia DR3 (see Section 2 in Clementini et al. 2023). However, in the reference paper (Clementini et al. 2016) and documentation of the tables gaiadr1.cepheid and gaiadr1.rrlyrae in Gaia DR1 as well as in the documentation of the tables gaiadr2.vari_cepheid and gaiadr2.vari_rrlyrae in Gaia DR2, it is incorrectly stated that the Fourier expansion is in sine functions.
Published September 2024