Gaia-ESO survey


The Gaia-ESO Public Survey

The Gaia-ESO Survey (GES)  is public spectroscopic survey conducted at VLT- UT2  employing the FLAMES multiobject spectrograph). It started on December 31, 2011 and ended in January 2017, for a total of 340 nights.


Overview of the observed fields and targets. The top panel shows the fraction of time dedicated to the different types of field: Milky Way, science open clusters, standards and calibrations (SD). The bottom panel shows the sky distribution for all the observations broken down by field type, using the same colour scheme



GES  has observed 115000 stars, systematically covering all major components of the Milky Way, from halo to star forming regions, providing the first homogeneous overview of the distributions of kinematics and elemental abundances. GES has also observed about 65 open clusters of all masses, metallicity, position in the disk, and ages (except the still embedded ones); GES also retrieved data for 20 additional clusters from the ESO archive and analyzed them with the same methods.


The co-PIs of GES were G. Gilmore (IoA, Cambridge) and S. Randich (INAF-OA Arcetri). The GES collaboration involved more than 400 reasearchers, mostly from European countries. The Italian contribution, beside the co-PI, waslarge. GES was organised in Working Groups, taking care of target selection, observation preparation, reduction, abundance analysis, etc.   Two of these WGs were coordinated by researcher at OAS Bologna,  Angela Bragaglia (WG4  – open cluster targets)  and Elena Pancino – presently at INAF Arcetri (WG5, calibrators & standards).  A few PhD and post-docs have been heavily involved in GES (e.g. Paolo Donati, Xiaoting Fu, Carmela Lardo)

All raw spectra  and all reduced (Phase 3) spectra are available from the ESO archive.

The final catalogue with radial velocities, stellar parameters, and abundances is available from the ESO Catalogue archive (here, Programme GAIAESO, version 3, public since 2022-05-16)


Participants at OAS :  M. BellazziniA. BragagliaF. CaluraD. RomanoM. Tosi

Participants formerly at OAS: G. Altavilla. M. Cignoni, G. Cocozza, P. Donati, G. Fiorentino, X. Fu, E. Pancino, S. Ragaini

Participants at DIFA:  G. Casali, C. Lardo, A. Miglio, A. Mucciarelli

For more details  see:

Gilmore et al. 2022 [The Gaia-ESO Public Spectroscopic Survey: Motivation, implementation, GIRAFFE data processing, analysis, and final data products]

Randich et al. 2022 [The Gaia-ESO Public Spectroscopic Survey: Implementation, data products, open cluster survey, science, and legacy]

Bragaglia et al. 2022 [The Gaia-ESO Survey: Target selection of open cluster stars]

[page prepared by Angela Bragaglia]