Gaia Early Data Release 3

Abstract

Aims. We produce a clean and well-characterised catalogue of objects within 100 pc of the Sun from the Gaia Early Data Release 3. We characterise the catalogue through comparisons to the full data release, external catalogues, and simulations. We carry out a first analysis of the science that is possible with this sample to demonstrate its potential and best practices for its use. Methods. Theselection of objects within 100 pc from the full catalogue used selected training sets, machine-learning procedures, astrometric quantities, and solution quality indicators to determine a probability that the astrometric solution is reliable. The training set construction exploited the astrometric data, quality flags, and external photometry. For all candidates we calculated distance posterior probability densities using Bayesian procedures and mock catalogues to define priors. Any object with reliable astrometry and a non-zero probability of being within 100 pc is included in the catalogue. Results. We have produced a catalogue of 331 312 objects that we estimate contains at least 92% of stars of stellar type M9 within 100 pc of the Sun. We estimate that 9% of the stars in this catalogue probably lie outside 100 pc, but when the distance probability function is used, a correct treatment of this contamination is possible. We produced luminosity functions with a high signal-to-noise ratio for the main-sequence stars, giants, and white dwarfs. We examined in detail the Hyades cluster, the white dwarf population, and wide-binary systems and produced candidate lists for all three samples. We detected local manifestations of several streams, superclusters, and halo objects, in which we identified 12 members of Gaia Enceladus. We present the first direct parallaxes of five objects in multiple systems within 10 pc of the Sun. Conclusions. We provide the community with a large, well-characterised catalogue of objects in the solar neighbourhood. This is a primary benchmark for measuring and understanding fundamental parameters and descriptive functions in astronomy.

Completeness of the Gaia-verse – IV. The astrometry spread function of Gaia DR2

“…1 respectively. Comparing with the Gaia Catalogue of Nearby Stars (Gaia Collaboration et al 2021b) there are sources extending out to the blue (𝐺 − 𝐺 RP < −1) and red (𝐺 − 𝐺 RP > 3) extremes of the colour distribution. The red sources will likely be extended sources or stars in crowded regions with high excess flux as mentioned in Section 2.…”

Astrometric identification of nearby binary stars II: Astrometric binaries in the Gaia Catalogue of Nearby Stars

“…We use only Gaia data, examining the DR2 and eDR3 results for stars in the GCNS (Gaia Collaboration et al 2021b). This sample of just over 300 000 stars within 100 pc has been significantly pruned to remove sources with spurious parallaxes using a random forest.…”

“…Many sub-populations, especially of evolved/bright stars are grouped together, and some (such as the Horizontal branch) even split between categories. The LMS group (and dim sources in general) also suffers from systematic issues with measurements of RP (and for studies of this region it is suggested that (BP − G) is a more representative colour metric Gaia Collaboration et al 2021b;Rybizki et al 2022) hence we will mostly exclude them from further analysis.…”

“…Thus, in this paper, we aim to set out and justify a minimal criteria to separate likely binary systems from both single stars and spurious astrometric solutions. In Section 2, we introduce the Gaia Catalogue of Nearby Stars (GCNS) (Gaia Collaboration et al 2021b) and show how and why we renormalise the UWE for this local sample. In section 3 we show the astrometric behaviour of all GCNS stars which pass our quality cuts.…”

MOBSTER -- VI. The crucial influence of rotation on the radio magnetospheres of hot stars

“…As a first step, the catalogue was cross-referenced with SIMBAD 1 , in order to obtain spectral types and Johnson photometry. Distances were obtained from the Gaia early Data Release 3 Catalogue (Gaia Collaboration et al 2021); in the few cases where these were not available, Hipparcos parallaxes (van Leeuwen 2007) generally were. Distances were calculated by inverting Gaussian parallax distributions, with the resulting asymmetric error bars propagated through to determinations of bolometric luminosity; however, in most cases the relative parallax errors are small enough (the median relative error is about 2%) that the difference between positive and negative distance uncertainties is negligible.…”