Gaia Data Release 1 (GDR1)

Content

Gaia DR1 is based on observations collected between 25 July 2014 and 16 September 2015.


Density map for gaiadr1.gaia_source (number of sources per square degree). Healpix based (nside 512, 3.14Mpixels)

**Source numbers**
Total number of sources 1,142,679,769
Number of TGAS* sources 2,057,050
– Hipparcos 93,635
– Tycho-2 1,963,415
Number of secondary sources** 1,140,622,719
Number of light curves for Cepheids 599
Number of light curves for RR Lyrae 2595

Magnitude distribution percentiles (G)

0.135% 11.2
2.275% 14.5
15.866% 17.1
50% 19.0
84.134% 20.1
97.725% 20.7
99.865% 21.0

* TGAS = Tycho-Gaia Astrometric Solution, also referred to as primary solution for primary sources.

** The astrometric solution of secondary sources (non-TGAS sources) is derived using the calibrations of the spacecraft attitude and the geometry of the instrument as `fixed’ input, as derived from the astrometric solution of primary sources (i.e., the TGAS solution).

Source: http://www.cosmos.esa.int/web/gaia/dr1