Gaia is a space observatory of the European Space Agency (ESA), launched in 2013 and expected to operate until at least 2022. The spacecraft carries a single integrated instrument that comprises three major functions: astrometry, photometry and spectrometry. The three functions use two common telescopes and a shared focal plane, with each function having a dedicated area on the large 0.5 m x 1 m charge-coupled device (CCD) Focal Plane Assembly detector array.


The spacecraft will measure approx. 1 billion stars with unprecedented precision. The spacecraft monitors each of its target objects about 70 times over the first five years of the mission. It targets objects brighter than magnitude 20 in a broad photometric band that covers most of the visual range. 


By early 2021 Gaia had classified ~550.000 sources as variable; for those the photometry is publicly available.


The successor to the Hipparcos mission (operational 1989–93), Gaia is part of ESA's Horizon 2000+ long-term scientific program. 



Phoranso makes use of data from the European Space Agency (ESA) mission Gaia, processed by the Gaia Data Processing and Analysis Consortium (DPAC). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. More information is also provided in following papers:  

  • Gaia Collaboration et al. (2016): Description of the Gaia mission (spacecraft, instruments, survey and measurement principles, and operations)
  • Gaia Collaboration et al. (2018b): Summary of the contents and survey properties.
  • Gaia Collaboration et al. (2016b): The Gaia mission (provides a description of the Gaia mission including spacecraft, instruments, survey and measurement principles, and operations)
  • Gaia Collaboration et al. (2020a): Gaia EDR3: Summary of the contents and survey properties.