Leicester astronomer pays tribute to ground-breaking Gaia mission
Credit: ESA/Gaia/DPAC, Stefan Payne-Wardenaar CC BY-SA 3.0 IGO or ESA standard License
A University of Leicester astronomer has paid tribute to a pioneering space telescope that has spent over a decade mapping our sky, as it ends its science observations today (15 Jan).
The European Space Agency’s Milky Way-mapper Gaia has completed the sky-scanning phase of its mission, racking up more than three trillion observations of about two billion stars and other objects over the last decade to revolutionise the view of our home galaxy and cosmic neighbourhood.
Launched on 19 December 2013, Gaia’s fuel tank is now approaching empty – it uses about a dozen grams of cold gas per day to keep it spinning with pinpoint precision. But this is far from the end of the mission. Technology tests are scheduled for the weeks ahead before Gaia is moved to its ‘retirement’ orbit, and two massive data releases are tabled for around 2026 and the end of this decade, respectively.
Researchers from the University of Leicester have been at the forefront of the Gaia Collaboration since its very earliest days.The University of Leicester team has had a critical role in the mission – they are responsible for understanding and compensating for radiation damage that affects the on-board sensors. If this isn’t done, all the critical science from the mission would be degraded. Over the lifetime of the project, the Leicester team has included Professor Martin Barstow, Drs Claudio Pagani, Steve Sembay, Andy Read, Duncan Fyfe and Patricio Ortiz.
They have also played an important role in the scientific publications that accompany the Gaia data releases, bringing their wider research expertise to illustrate how Gaia data can be used. Leicester led work on the study of binary star systems revealed by Gaia and created a catalogue of 100,000 white dwarf stars that has been released to the community. They have also used machine learning techniques to classify the white dwarfs and determine their temperature and masses, providing a valuable resource for the field.
Professor Barstow, Director of Strategic Partnerships at the University’s £100 million science and innovation park Space Park Leicester, said: “The Gaia mission has delivered an amazing legacy, transforming astrophysics. It is sad that the spacecraft operations are coming to an end, but we have been able to observe for twice as long as originally planned. Also, the project will continue to analyse the data and publish new catalogues until at least 2030. The Gaia astronomical revolution will continue!”
Credit: ESA/Gaia/DPAC, Stefan Payne-Wardenaar CC BY-SA 3.0 IGO or ESA standard License
Gaia has been charting the positions, distances, movements, brightness changes, composition and numerous other characteristics of stars by monitoring them with its three instruments many times over the course of the mission.
This has enabled Gaia to deliver on its primary goal of building the largest, most precise map of the Milky Way, showing us our home galaxy like no other mission has done before.
As such, we now also have the best reconstructed view of how our galaxy might look to an outside observer. This new artist impression of the Milky Way incorporates Gaia data from a multitude of papers over the past decade.
Gaia’s repeated measurements of stellar distances, motions and characteristics are key to performing ‘galactic archaeology’ on our Milky Way, revealing missing links in our galaxy’s complex history to help us learn more about our origins. From detecting ‘ghosts’ of other galaxies and multiple streams of ancient stars that merged with the Milky Way in its early history, to finding evidence for an ongoing collision with the Sagittarius dwarf galaxy today, Gaia is rewriting the Milky Way’s history and making predictions about its future.
In the process of scanning the stars in our own galaxy, Gaia has also spotted other objects, from asteroids in our Solar System backyard to galaxies and quasars – the bright and active centres of galaxies powered by supermassive black holes – outside our Milky Way.
The Gaia scientific and engineering teams are already working full steam on the preparations for Gaia Data Release 4 (DR4), expected in 2026. The data volume and quality improves with every release and Gaia DR4, with an expected 500 TB of data products, is no exception. Furthermore, it will cover the mission’s first 5.5 years, corresponding to the length of the originally foreseen duration of the mission.
“Today marks the end of science observations and we are celebrating this incredible mission that has exceeded all our expectations, lasting for almost twice its originally foreseen lifetime,” says ESA Director of Science Carole Mundell.
“The treasure trove of data collected by Gaia has given us unique insights into the origin and evolution of our Milky Way galaxy, and has also transformed astrophysics and Solar System science in ways that we are yet to fully appreciate. Gaia built on unique European excellence in astrometry and will leave a long-lasting legacy for future generations."