Hipparcos2 Neighbourhood (gaiadr3.hipparcos2_neighbourhood)

The table has 100009 rows, 5 columns.


Table hipparcos2_neighbourhood includes all good neighbours for each matched Hipparcos2 object. A good neighbour for a given Hipparcos2 source is a nearby Gaia object whose position is compatible (within position errors) with the Hipparcos2 target. The cross-match algorithm is not symmetric and searches Hipparcos2 sources counterparts in Gaia. The cross-match algorithm is positional and exploits the full 5 parameter covariance matrix of the Gaia astrometric solution when available and the external catalogue positions and position errors. In addition it takes into account the Gaia environment using the local density.

Please note that the cross-match algorithm is a trade-off between multiple requirements, in particular between completeness and correctness. It is thus not limited to a simple cone search.

Reference papers:

  • Marrese et al. (2017)
  • Marrese et al. (2019)


If you have used Gaia data in your research, please use the following acknowledgement:

This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement.

More information can be found on the credit and citation instructions page.


Name Type UCD Unit Description
source_id long meta.id

Unique Gaia source identifier

original_ext_source_id integer meta.id.cross

Original External Catalogue source identifier

angular_distance float pos.angDistance arcsec

Angular Distance between the two sources

score double meta.code

Score of neighbours

xm_flag short meta.code.status

Cross-match algorithm flag