The main objective of the gaiasupdate package is the computation of the astrometric source parameters, e.g. the parallax and proper motions, from Gaia astrometric timeseries data, also known as Gaia "epoch astrometry".
The fourth Gaia data release (Gaia DR4) will publish the astrometric source parameters alongside with timeseries of individual positional measurements, i.e. the epoch astrometry which will be available via DataLink or bulk download. The gaiasupdate software package allows users to compute the former on the basis of the latter, to the extent possible.
- Compute astrometric source parameters on the basis of epoch astrometry data.
Note that the epoch data of all sources will not be publicly available until the Gaia DR4 release. However, epoch astrometry of a small sample of sources was pre-released in advance of Gaia DR4.
gaiasupdate is a shorthand for "Gaia source update", where "source update" refers to the determination of a source's astrometric parameters. This namenclature originates in the corresponding step of the astrometric global iterative solution, see Lindegren et al. 2012 (Sect. 4.1).
This package requires Python >= 3.9 and the following dependencies:
- numpy
- scipy
- pandas
- astropy
- pyarrow
- astroquery
See requirements.txt file for more details.
git clone https://github.com/esa/gaia-supdate
cd gaiasupdate
pip install -e .
pip install gaiasupdate
A notebook to show how to use gaiasupdate to compute source astrometric parameters from epoch astrometry data can be found at https://github.com/esa/gaia-jupyter-notebooks/tree/main/data-release-4-tutorials
There are also tests included in this package to show:
- how to produce the astrometric parameters of a source using epoch data: Test source update
The package documentation can be found at https://esa.github.io/gaia-supdate.
If you make use of gaiasupdate in your research or otherwise, we would appreciate a citation of 
"This work made use of the gaiasupdate package that is described at https://www.cosmos.esa.int/web/gaia/gaia-source-update.
More information on how to acknowledge Gaia resources is available at Gaia credits and acknowledgements.
This code was written by A. Delgado and J. Sahlmann with contributions by A. Bombrun, L. Lindegren, and others in the Gaia collaboration.
The details of the license of this package can be found in the file LICENSE.txt.
European Space Agency Public License (ESA-PL) Permissive (Type 3) – v2.4.