Opening a real-time window to our vast and ever-changing skies
25 February 2026
As the Vera C. Rubin Observatory issues its first live alerts of changes detected in the night sky, a UK innovation is allowing us to observe millions of astronomical events as they unfold.
A UK-developed software system is allowing astronomers around the world to quickly pinpoint previously invisible phenomena in a sky littered with stars. Lasair, a platform created by a team from Queen’s University Belfast, the University of Edinburgh and the University of Oxford, will start to filter millions of events from the Rubin public alerts stream to unlock new scientific opportunities faster than ever before.
More than a decade in development, Lasair is one of a handful of Rubin data brokers. As a specialist in detecting transient events, it will uncover explosions of stars in distant galaxies that can tell us about the origin of the elements, the expansion of the Universe and the complex physics of black holes.
Lasair will ingest, process, and filter millions of astronomical alerts from the data that Rubin will capture during its 10-year Legacy Survey of Space and Time (LSST). This will enable scientists to focus on significant changes in the sky, from supernovae, variable stars, and gamma-ray bursts to black holes eating stars, and asteroids in the Solar System.
The first Rubin Observatory alerts distributed to researchers around the world were generated on the night of 24 February. The alerts contained the flares of new supernovae and the flickers of stars, actively feeding black holes in distant galaxies, and asteroids cruising through our Solar System.
A deluge of data
Every night, powerful computers in the UK will help to wrangle the huge influx of data captured by the world’s largest digital camera before serving it up to the science community through the Lasair web portal. The computers that run Lasair are part of a wider data facility constructed on IRIS (Infrared Imaging Spectrograph), a network of powerful, digital research infrastructure for priority astronomy, particle physics, and nuclear physics in the UK. IRIS provides the technology that astronomers around the world will use to unlock the secrets from Rubin.
Over the next 10 years, UK scientists will use powerful supercomputers to analyse around 10 million images, captured by the Observatory as part of LSST, identifying and measuring billions of stars and galaxies – most of which have never previously been detected.
Dr Roy Williams of the University of Edinburgh has been the lead developer for Lasair for over a decade. He said: “Lasair is a platform to enable custom filtering: each user imagines and creates their own filter. Most nights there will be a massive flow of data that Lasair will strain through those filters, and we hope this flexibility will allow users to find new and unexpected discoveries from this glorious deluge.”
Professor Stephen Smartt, the Wetton Professor of Astrophysics at the University of Oxford, is the scientific lead of the Lasair team. He said: “The data that Lasair will serve up – not only to the scientific community but also to the general public – will enable early Rubin science. Lasair is a Gaelic word that means ‘flame’ or ‘flash’; our broker will enable users to detect things that move and explode in the sky, within minutes of the image being taken in Chile.
“The Rubin Observatory uses the largest camera ever built for astronomy, and for 10 years it will take an image every 30 seconds. Every night, these images are likely to contain around seven million sources that have changed in some way. Each of those images are likely to contain 10 million sources that have changed in some way. Lasair will match all of those to every major astronomical catalogue that exists and give an initial classification – variable star, active galactic nucleus, a supernova near a known galaxy – and match these sources to gamma-ray burst and x-rays detected from space telescopes in real time. We are providing a platform for any scientist in the world to connect to and find new explosions in the nearby and distant Universe.”
Sophisticated software
Professor Bob Mann, Professor of Survey Astronomy at the University of Edinburgh, is the Project Leader for UK participation in the Rubin LSST. He said: “The Lasair alert broker is one of the important contributions that UK astronomers are making to the Rubin LSST. Over the course of a decade, the Lasair team have used data from simulations and a precursor sky survey to develop a sophisticated system that will enable astronomers to detect instances of rare time-varying celestial phenomena of different kinds within the deluge of data that will flow from Rubin. Today marks a major milestone for them and the start of an exciting decade of science for astronomers in the UK and beyond.”
UK investment
Lasair is part of a multi-million-pound investment by the Science and Technology Facilities Council (STFC), which is enabling the UK to participate in the groundbreaking Rubin LSST. Across 36 research institutions in the UK, researchers and software developers are addressing scientific and technical challenges that will enable astronomers to make discoveries within the multi-Petabyte dataset that will be captured by the Rubin Observatory over the next 10 years.
The beginning of scientific alerts is one of the last major milestones before Rubin Observatory begins its Legacy Survey of Space and Time (LSST) this year.
Further information
About Lasair
Lasair is part of Rubin UK (LSST:UK) and one of seven independent Rubin brokers, Lasair will also share classifications from three other Rubin community brokers: Fink (France), AMPEL (Germany), and Alerce (Chile).
Lasair website
Technical notes on Lasair
About LSST:UK
To date, UK participation in the Rubin LSST has been funded by £23 million of investment by the Science and Technology Facilities Council (STFC), part of UK Research and Innovation. Computational resources used by LSST:UK are provided through the STFC-funded IRIS project.
Formed in 2014, the LSST:UK Consortium is made up of 36 partners representing all major UK astronomy research groups.
The LSST:UK Consortium has created the LSST:UK Science Centre (LUSC), a distributed team of researchers and software developers addressing scientific and technical challenges that will enable astronomers to make discoveries within the multi-Petabyte dataset produced by LSST.
Visit www.rubin.ac.uk
About the NSF–DOE Vera C. Rubin Observatory
The NSF–DOE Vera C. Rubin Observatory is jointly funded by the U.S. National Science Foundation and the U.S. Department of Energy’s Office of Science. Rubin Observatory is a joint Programme of NSF NOIRLab and DOE’s SLAC National Accelerator Laboratory.
Rubin’s 3200-megapixel camera is the world’s largest digital camera. It’s the size of a car and weighs around 2,800kg. During its 10-year survey, Rubin will catalogue an estimated 17 billion stars, 20 billion galaxies, and millions of transients – more objects than there are living people on earth.
Video (YouTube): Rubin difference imaging