#End of the world astrometry how to#
#End of the world astrometry full#

For a subset of about 87 million sources also the line-of-sight extinction AG and reddening E(BP-RP) are given and for a part of this subset (around 76 million sources) the luminosity and radius are available as well.

Subject to limitations (see below) the effective temperatures Teff for more than 161 million sources brighter than 17th magnitude with effective temperatures in the range 3000 to 10,000 K.

The transit observations are part of Gaia DR2 and have also been delivered to the Minor Planet Center (MPC). 96% of the along-scan (AL) residuals are in the range -5 to 5 mas, and 52% of the AL residuals are in the range of -1 to 1 mas.

Epoch astrometry for 14,099 known solar system objects based on more than 1.5 million CCD observations.

These passbands are now available for download.

#End of the world astrometry full#

Full passband definitions for G, BP and RP.GBP and GRP magnitudes for more than 1.38 billion sources, with precisions varying from a few milli-mag at the bright (GPlease be aware that the photometric system for the G band in Gaia DR2 is different from the photometric system as used in Gaia DR1. G magnitudes for more than 1.69 billion sources, with precisions varying from around 1 milli-mag at the bright (G<13) end to around 20 milli-mag at G=20. These sources have a positional uncertainty at G=20 of about 2 mas, at J2015.5. An additional set of more than 361 million sources for which a two-parameter solution is available: the positions on the sky (α, δ) combined with the mean G magnitude.The overall precision of the radial velocities at the bright end is in the order of 200-300 m s-1 while at the faint end the overall precision is approximately 1.2 km s-1 for a Teff of 4750 K and about 2.5 km s-1 for a Teff of 6500 K. This leads to a full six-parameter solution: positions and motions on the sky with parallaxes and radial velocities, all combined with mean G magnitudes. the median value over the epochs) for more than 7.2 million stars with a mean G magnitude between about 4 and 13 and an effective temperature (Teff) in the range of about 3550 to 6900 K. The Gaia DR2 parallaxes and proper motions are based only on Gaia data they do no longer depend on the Tycho-2 Catalogue. The corresponding uncertainties in the respective proper motion components are up to 0.06 mas yr-1 (for G < 15 mag), 0.2 mas yr-1 (for G = 17 mag) and 1.2 mas yr-1 (for G = 20 mag). Parallax uncertainties are in the range of up to 0.04 milliarcsecond for sources at G < 15, around 0.1 mas for sources with G=17 and at the faint end, the uncertainty is of the order of 0.7 mas at G = 20. The five-parameter astrometric solution – positions on the sky (α, δ), parallaxes, and proper motions – for more than 1.3 billion (109) sources, with a limiting magnitude of G = 21 and a bright limit of G ≈ 3.Here’s a (brief!) list of the contents of DR2:

#End of the world astrometry how to#

You can find links to all the DR2 science papers here, a guide to how to use the data here, and of course a link to the full Gaia Archive here. This amounts to about 1 per cent of the Galactic stellar population. Gaia will provide unprecedented positional and radial velocity measurements with the accuracy needed to produce a stereoscopic and kinematic census of about one billion stars in our Galaxy and throughout the Local Group. In case you weren’t aware, Gaia is an ambitious space mission to chart a three-dimensional map of our Galaxy, the Milky Way, in the process revealing the composition, formation and evolution of the Galaxy. In fact it was way back in 2016! Anyway, yesterday came another glut of Gaia goodness in the form of the second release of data, known to its friends as DR2.

It seems like only yesterday that I was blogging excitedly about the first release of data (DR1) from the European Space Agency’s Gaia Mission.