Gaia Data Release 2

After several weeks of work, the second catalogue of the Gaia mission is now integrated into WinStars.

As a reminder, the Gaia mission is designed to map in 3D a part of the Milky Way (1%), with an evaluation of the proper velocity of the celestial bodies identified. A herculean task made by a satellite located at Lagrange 2 point that performs 500 million measurements every day.

The old Sky2000, UCAC4 and I/280B catalogues have therefore been abandoned to be replaced by the 1.7 billion stars (!) contained in this second edition published in April 2018, just one year ago.

Since it is not reasonable to get all the data from the DR2, WinStars only uses right ascension, declination, parallax, proper motion and magnitude G for objects with a magnitude less than 13. Beyond this limit, the program only retrieves positions on the sky and magnitude.

A version 3 in 2022

But the Gaia mission’s measurement campaign continues. A version 3 of the catalogue is planned for 2022 with increased data accuracy.

We are only at the beginning of the mission. In the long run, it is the entire structure of our galaxy, its dynamics and evolution that will be better understood by analyzing this gigantic mass of information.

Scientific data freely accessible through CDS

I would like to conclude by acknowledging the work of the Centre de Données de Strasbourg, a virtual memory of the sky, which makes available all the data collected from the largest observatories and from Gaia-type collaborations.
Thus, the data coming from a satellite located at two million km from Earth can be included in software such as WinStars a few months later.

In an age of fake news and other conspiracy theories, access to knowledge obtained through the disinterested work of thousands of scientists dispersed throughout the world has never been, paradoxically, so simple.


WinStars uses the Gaia DR2 catalogue to display stars up to magnitude 20. Here, the globular cluster Messier 13.

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