̽��ֱ�� of Cambridge - Nicholas Walton

Farewell, Gaia: spacecraft operations come to an end

sc604 — Thu, 27 Mar 2025 10:27:38 +0000

On 27 March 2025, Gaia’s control team at ESA’s European Space Operations Centre switched off the spacecraft’s subsystems and sent it into a ‘retirement orbit’ around the Sun.

Though the spacecraft’s operations are now over, the scientific exploitation of Gaia’s data has just begun.

Launched in 2013, Gaia has transformed our understanding of the cosmos by mapping the positions, distances, motions, and properties of nearly two billion stars and other celestial objects. It has provided the largest, most precise multi-dimensional map of our galaxy ever created, revealing its structure and evolution in unprecedented detail.

̽��ֱ��mission uncovered evidence of past galactic mergers, identified new star clusters, contributed to the discovery of exoplanets and black holes, mapped millions of quasars and galaxies, and tracked hundreds of thousands of asteroids and comets. ̽��ֱ��mission has also enabled the creation of the best visualisation of how our galaxy might look to an outside observer.

“ ̽��ֱ��data from the Gaia satellite has and is transforming our understanding of the Milky Way, how it formed, how it has evolved and how it will evolve,” said Dr Nicholas Walton from Cambridge’s Institute of Astronomy, lead of the Gaia UK project team. “Gaia has been in continuous operation for over 10 years, faultless, without interruption, reflecting the quality of the engineering, with significant elements of Gaia designed and built in the UK. But now it is time for its retirement. Gaia has finished its observations of the night sky. But the analysis of the Gaia mission data continues. Later in 2026 sees the next Gaia Data Release 4, to further underpin new discovery unravelling the beauty and mystery of the cosmos.”

Gaia far exceeded its planned lifetime of five years, and its fuel reserves are dwindling. ̽��ֱ��Gaia team considered how best to dispose of the spacecraft in line with ESA’s efforts to responsibly dispose of its missions.

They wanted to find a way to prevent Gaia from drifting back towards its former home near the scientifically valuable second Lagrange point (L2) of the Sun-Earth system and minimise any potential interference with other missions in the region.

“Switching off a spacecraft at the end of its mission sounds like a simple enough job,” said Gaia Spacecraft Operator Tiago Nogueira. “But spacecraft really don’t want to be switched off.

“We had to design a decommissioning strategy that involved systematically picking apart and disabling the layers of redundancy that have safeguarded Gaia for so long, because we don’t want it to reactivate in the future and begin transmitting again if its solar panels find sunlight.”

On 27 March, the Gaia control team ran through this series of passivation activities. One final use of Gaia’s thrusters moved the spacecraft away from L2 and into a stable retirement orbit around the Sun that will minimise the chance that it comes within 10 million kilometres of Earth for at least the next century.

̽��ֱ��team then deactivated and switched off the spacecraft’s instruments and subsystems one by one, before deliberately corrupting its onboard software. ̽��ֱ��communication subsystem and the central computer were the last to be deactivated.

Gaia’s final transmission to ESOC mission control marked the conclusion of an intentional and carefully orchestrated farewell to a spacecraft that has tirelessly mapped the sky for over a decade.

Though Gaia itself has now gone silent, its contributions to astronomy will continue to shape research for decades. Its vast and expanding data archive remains a treasure trove for scientists, refining knowledge of galactic archaeology, stellar evolution, exoplanets and much more.

“No other mission has had such an impact over such a broad range of astrophysics. It continues to be the source of over 2,000 peer-reviewed papers per year, more than any other space mission,” said Gaia UK team member Dr Dafydd Wyn Evans, also from the Institute of Astronomy. “It is sad that its observing days are over, but work is continuing in Cambridge, and across Europe, to process and calibrate the final data so that Gaia will still be making its impact felt for many years in the future.”

A workhorse of galactic exploration, Gaia has charted the maps that future explorers will rely on to make new discoveries. ̽��ֱ��star trackers on ESA’s Euclid spacecraft use Gaia data to precisely orient the spacecraft. ESA’s upcoming Plato mission will explore exoplanets around stars characterised by Gaia and may follow up on new exoplanetary systems discovered by Gaia.

̽��ֱ��Gaia control team also used the spacecraft’s final weeks to run through a series of technology tests. ̽��ֱ��team tested Gaia’s micro propulsion system under different challenging conditions to examine how it had aged over more than ten years in the harsh environment of space. ̽��ֱ��results may benefit the development of future ESA missions relying on similar propulsion systems, such as the LISA mission.

̽��ֱ��Gaia spacecraft holds a deep emotional significance for those who worked on it. As part of its decommissioning, the names of around 1500 team members who contributed to its mission were used to overwrite some of the back-up software stored in Gaia’s onboard memory.

Personal farewell messages were also written into the spacecraft’s memory, ensuring that Gaia will forever carry a piece of its team with it as it drifts through space.

As Gaia Mission Manager Uwe Lammers put it: “We will never forget Gaia, and Gaia will never forget us.”

̽��ֱ��Cambridge Gaia DPAC team is responsible for the analysis and generation of the Gaia photometric and spectro-photometric data products, and it also generated the Gaia photometric science alert stream for the duration of the satellite's in-flight operations.

Adapted from a media release by the European Space Agency.

̽��ֱ��European Space Agency’s Gaia spacecraft has been powered down, after more than a decade spent gathering data that are now being used to unravel the secrets of our home galaxy.

ESA/Gaia/DPAC, Stefan Payne-Wardenaar

Artist's impression of the Milky Way

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

Licence type:

Attribution-ShareAlike

Last starlight for ground-breaking Gaia

Anonymous — Wed, 15 Jan 2025 09:22:32 +0000

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.

“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,” said ESA Director of Science Carole Mundell.

“ ̽��ֱ��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.”

“Today marks the last day of science data collection from Gaia, these observations to form part of the final data release,” said Dr Nicholas Walton from Cambridge’s Institute of Astronomy, lead of the UK Gaia Project team and ESA Gaia Science Team member. “Our Gaia team in the UK is now working hard on the incredibly complex data analysis for the upcoming Gaia data releases. These will enable a wealth of new discovery, adding to the science from one of the world’s most productive science discovery machines.”

Gaia delivers best Milky Way map

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 throughout 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.

Gaia’s repeated measurements of stellar distances, motions and characteristics are key to performing ‘galactic archeology’ 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.

Warning! More ground-breaking science ahead

̽��ֱ��Gaia scientific and engineering teams are already working on the preparations for Gaia Data Release 4 (DR4), expected in 2026.

“This is the Gaia release the community has been waiting for, and it’s exciting to think this only covers half of the collected data,” said Antonella Vallenari, Deputy Chair of DPAC based at the Istituto Nazionale di Astrofisica (INAF), Astronomical Observatory of Padua, Italy. “Even though the mission has now stopped collecting data, it will be business as usual for us for many years to come as we make these incredible datasets ready for use.”

“Over the next months we will continue to downlink every last drop of data from Gaia, and at the same time the processing teams will ramp up their preparations for the fifth and final major data release at the end of this decade, covering the full 10.5 years of mission data,” said Rocio Guerra, Gaia Science Operations Team Leader based at ESA’s European Space Astronomy Centre (ESAC) near Madrid in Spain.

Gaia’s retirement plan

While today marks the end of science observations, a short period of technology testing now begins. ̽��ֱ��tests have the potential to further improve the Gaia calibrations, learn more about the behaviour of certain technology after ten years in space, and even aid the design of future space missions.

After several weeks of testing, Gaia will leave its current orbit around Lagrange point 2, 1.5 million km from the Earth in the direction away from the Sun, to be put into its final heliocentric orbit, far away from Earth’s sphere of influence. ̽��ֱ��spacecraft will be passivated on 27 March 2025, to avoid any harm or interference with other spacecraft.

Wave farewell to Gaia

During the technology tests Gaia’s orientation will be changed, meaning it will temporarily become several magnitudes brighter, making observations through small telescopes a lot easier (it won’t be visible to the naked eye). A guide to locating Gaia has been set up here, and amateur astronomers are invited to share their observations.

“Gaia will treat us with this final gift as we bid farewell, shining among the stars ahead of its well-earned retirement,” said Uwe Lammers, Gaia Mission Manager.

“It’s a moment to celebrate this transformative mission and thank all of the teams for more than a decade of hard work operating Gaia, planning its observations, and ensuring its precious data are returned smoothly to Earth.”

Adapted from a European Space Agency press release.

̽��ֱ��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.

ESA/Gaia/DPAC, Stefan Payne-Wardenaar

This is a new artist’s impression of our galaxy, the Milky Way, based on data from ESA’s Gaia space telescope.

Yes

Licence type:

Attribution-ShareAlike

Cancer researchers and astronomers join forces in fight against disease

Anonymous — Fri, 13 Sep 2024 14:21:05 +0000

̽��ֱ��technology from Cancer Grand Challenges team IMAXT uses advanced spatial biology techniques to analyse tumours, some of which are based on technology originally developed to map the Milky Way and discover new planets. Now, other scientists will be able to access these technologies to create detailed tumour maps that could one day transform how we diagnose and treat cancer.

Led by Professor Greg Hannon and Dr Dario Bressan at the Cancer Research UK Cambridge Institute and Dr Nicholas Walton at the ̽��ֱ�� of Cambridge’s Institute of Astronomy, SPACE will give other researchers the opportunity to study cancer in a way that wasn’t previously possible.

Dr Dario Bressan, Head of the SPACE Laboratory at the Cancer Research UK Cambridge Institute, said: “Tumours aren’t just a uniform mass of cells; they consist of a diverse ecosystem of cancer cells, immune cells, and other essential components that support their survival. Hidden within these intricate networks lies valuable information which could guide us in making more personalised treatment decisions for each patient.

“With the SPACE platform, researchers can zoom into specific cell populations, highlight the complex connections between them, and even run virtual experiments to predict how the tumour might respond to different treatments. By unlocking these insights, we can transform the future of cancer care and uncover new opportunities for targeted therapies.”

̽��ֱ��IMAXT team was first awarded £20 million in 2017 by Cancer Research UK through Cancer Grand Challenges, a global research initiative co-founded by Cancer Research UK and the National Cancer Institute in the US.

Since then, the team has united experts from fields rarely brought together including medicine, Virtual Reality (VR), programming, molecular biology, chemistry, mathematics, and even astronomy, to create a completely immersive tool for studying tumours.

As well as enabling scientists to analyse 3D tumour maps, IMAXT created pioneering VR technology which allows the user to ‘step inside’ a tumour using a VR headset.

With the headset, scientists get to view vast amounts of detailed data about individual tumour cells in a 3D space. Instead of looking at this data on a computer screen, they can see all the information in real-time, as if they were inside the tumour itself.

Professor Greg Hannon, Director of the Cancer Research UK Cambridge Institute, said: "Cancer Grand Challenges offers a unique opportunity for international teams to address some of cancer’s biggest challenges. When we took on our particular challenge, much of what we proposed was science fiction.

“Over the past 7 years, our team has turned those early hopes and ideas into approaches that can now be made broadly available. In nature, biology unfolds in three dimensions, and we now finally have the tools to observe it that way—giving us a much deeper, more accurate view of cancer. We’re thrilled to share these breakthroughs with the broader cancer research community."

ioa-space-image_full.jpg

Director of Cancer Grand Challenges at Cancer Research UK, Dr David Scott, said: “IMAXT is changing what’s possible when it comes to cancer research.

“We can glean important insights about a tumour by analysing its genetic makeup or its proteins, but no technology alone can give us the depth of understanding needed to truly understand this complex disease.

“By combining state-of-the-art technology and vast expertise, IMAXT will change how cancers are classified, treated and managed, giving more people a better chance of surviving their disease.”

̽��ֱ��funding will support the SPACE hub laboratory, hosted at the CRUK Cambridge Institute, and the SPACE analysis and computing platform, developed and operated at the Institute of Astronomy, ̽��ֱ�� of Cambridge. Together SPACE includes and combines most available technologies for the spatial molecular profiling of tumours. ̽��ֱ��continued collaboration between the cancer and astronomy teams from the IMAXT project will ensure the maintenance and development of all critical aspects of the platform – from technical and scientific expertise to instrumentation, computing, and data analysis – to allow SPACE to continue at the forefront research in the rapidly emerging spatial-omics field, and be a valuable centre of excellence to support new research in the Cancer Grand Challenge and cancer research communities.

SPACE is funded by Cancer Research UK through Cancer Grand Challenges. Additional support for the SPACE project has been provided by the UK Space Agency through their funding of the development of imaging and analysis techniques at the IoA, Cambridge for a range of space science missions. These have been successfully applied to spatial imaging data through IMAXT and are ready for wider use in SPACE.

Dr Paul Bate, Chief Executive Officer at UK Space Agency said: “Space is powering our daily lives, from satellite navigation to weather forecasts and climate monitoring. This collaboration between the cancer and astronomy teams in the IMAXT project is another real-world example of how space science and technology is bringing benefits to people here on Earth.

“Thanks to this partnership, the same science and technology that mapped the Milky Way may soon have a positive impact on people battling cancer, and could support doctors to provide better, faster treatment."

Going forward, a next-generation version of the VR technology will be further developed and commercialised by Suil Vision, a start-up company recently launched by IMAXT team members and Cancer Research UK’s innovation arm, Cancer Research Horizons. Suil Vision is the first start-up to emerge from the Cancer Grand Challenges programme. With a £500,000 investment from the Cancer Research Horizons Seed Fund, Suil Vision will create a market-ready version of their suite of VR technologies for analysing multiple types of biological data, rolling these out across research institutions and companies worldwide.

Find out how Cambridge is changing the story of cancer

Image

Top: Lung with two metastatic lesions derived from a mouse primary triple-negative breast tumour. ̽��ֱ��figure shows how the registration of the different imaging modalities to a cellular level allow to segment individual cells and identify tumour cell populations, differentiate hypoxic areas, increased fibrosis, infiltration of immune cells and blood and lymphatic vessels by staining with a panel of 35 cell markers at the same time. Bottom: Sample in 3D depicts a tumour grown in the mammary gland of a mouse showing the power of the SPACE pipeline to produce and visualise large volumes (typically ~100,000 individual images registered and stitched and up to 500TB 500 GB of data). ̽��ֱ��orange fluorescence beads are clearly visible in the medium outside the biological tissue and prove to be crucial for all stages of multimodal registration.

Adapted from a press release by Cancer Research UK

A unique collaboration of astronomers and cancer researchers at Cambridge has been awarded more than £5m to establish the Spatial Profiling and Annotation Centre of Excellence (SPACE) to open up access to their groundbreaking cancer mapping technology and establish collaborations with other scientists to enable them to investigate tumours in 3D.

When we took on our particular challenge, much of what we proposed was science fiction

Greg Hannon

SPACE Laboratory

Lung with two metastatic lesions derived from a mouse primary triple-negative breast tumour

Yes

Licence type:

Attribution

Latest Gaia data release reveals rare lenses, cluster cores and unforeseen science

sc604 — Tue, 10 Oct 2023 12:47:51 +0000

Gaia is mapping our galaxy and beyond in multi-dimensional detail, completing the most accurate stellar census ever. ̽��ֱ��mission is painting a detailed picture of our place in the Universe, enabling us to better understand the diverse objects within it.

̽��ֱ��mission’s latest data release provides new and improved insights into the space around us. ̽��ֱ��release also brings findings that go far beyond what Gaia was initially designed to discover and digs deep into our cosmic history.

“This focused product data release will open up new insights across astronomy, from the precise orbits of asteroids in our Solar System, to quasar discovery in the distant cosmos,” said Dr Nicholas Walton from Cambridge’s Institute of Astronomy, lead of the UK Gaia Project team and ESA Gaia Science Team member. “It demonstrates the breadth of science enabled by Gaia, and the role of Cambridge and UK Gaia teams in the creation of these data products. This release represents but a small taste of the riches to be revealed with the publication of the next full release, Gaia DR4.”

So – what’s new from Gaia?

Half a million new stars: Gaia's observing mode extended to unlock cluster cores

Gaia’s third data release (DR3) contained data on over 1.8 billion stars, building a pretty complete view of the Milky Way and beyond. However, there remained gaps in our mapping. Gaia had not yet fully explored areas of sky that were especially densely packed with stars, leaving these comparatively unexplored – and overlooking stars shining less brightly than their many neighbours.

Globular clusters are a key example of this. These clusters are some of the oldest objects in the Universe, making them especially valuable to scientists looking at our cosmic past. Unfortunately, their bright cores, chock-full of stars, can overwhelm telescopes attempting to get a clear view. As such, they remain missing pieces in our maps of the Universe.

To patch the gaps in our maps, Gaia selected Omega Centauri, the largest globular cluster that can be seen from Earth. Rather than just focusing on individual stars, as it typically would, Gaia enabled a special mode to truly map a wider patch of sky surrounding the cluster’s core every time the cluster came into view.

“In Omega Centauri, we discovered over half a million new stars Gaia hadn't seen before – from just one cluster!” says lead author Katja Weingrill of the Leibniz-Institute for Astrophysics Potsdam (AIP), Germany, and a member of the Gaia collaboration.

“Through a new use of one of Gaia’s specialised engineering modes, we have been able to generate an imaging catalogue of some of the densest stellar fields in our galaxy,” said Dr Dafydd Wyn Evans, lead of the Gaia photometric development team. “This is enabling us to provide a more complete view of all components of the Milky Way, including the cores of Globular Clusters, some of the oldest structures in our Galaxy.”

This finding not only meets but actually exceeds Gaia’s planned potential. ̽��ֱ��team used an observing mode designed to ensure that all of Gaia’s instruments are running smoothly.

“ ̽��ֱ��Gaia Sky Mapper images required the development of a new processing pipeline to measure the accurate brightness of the hundreds of thousands faint stars not seen by Gaia before,” said Dr Francesca De Angeli, lead of Gaia’s Photometric Data Processing Centre in Cambridge. “This rich data probes regions of the sky previously unseen by Gaia, and fills in important gaps in earlier data releases.”

̽��ֱ��new stars revealed in Omega Centauri mark one of the most crowded regions explored by Gaia so far.

Gaia is currently exploring eight more regions in this way, with the results to be included in Gaia Data Release 4. These data will help astronomers to truly understand what is happening within these cosmic building blocks, a crucial step for scientists aiming to confirm the age of our galaxy, locate its centre, figure out whether it has gone through any past collisions, verify how stars change through their lifetimes, constrain our models of galactic evolution, and ultimately infer the possible age of the Universe itself.

Looking for lenses: Gaia the accidental cosmologist

While Gaia was not designed for cosmology, its new findings peer deep into the distant Universe, hunting for elusive and exciting objects that hold clues to some of humanity’s biggest questions about the cosmos: gravitational lenses.

Gravitational lensing occurs when the image of a faraway object becomes warped by a disturbing mass – a star or galaxy, for instance – sitting between us and the object. This intermediate mass acts as a giant magnifying glass, or lens, that can amplify the brightness of light and cast multiple images of the faraway source onto the sky. These rare configurations hold immense scientific value, revealing clues about the earliest days of the Universe.

̽��ֱ��team identified the candidates from an extensive list of possible quasars (including those from Gaia DR3). Five of the possible lenses are potential Einstein crosses, rare lensed systems with four different image components shaped like a cross. (See 12 such configurations discovered by Gaia in 2021.)

Finding lensed quasars is challenging. A lensed system’s constituent images can clump together on the sky in misleading ways, and most are very far away, making them faint and tricky to spot.

Extending Gaia’s value into cosmology brings synergy with ESA’s Euclid mission, recently launched on its quest to explore the dark Universe. While both focus on different parts of the cosmos – Euclid on mapping billions of galaxies, Gaia on mapping billions of stars – the lensed quasars discovered by Gaia can be used to guide future exploration with Euclid.

Asteroids, stacked starlight and pulsating stars

Other papers published today offer further insight into the space around us, and the diverse and sometimes mysterious objects within it.

One reveals more about 156,823 of the asteroids identified as part of Gaia DR3. ̽��ֱ��new dataset pinpoints the positions of these rocky bodies over nearly double the previous timespan, making most of their orbits – based on Gaia observations alone – 20 times more precise. In the future, Gaia DR4 will complete the set and include comets, planetary satellites and double the number of asteroids, improving our knowledge of the small bodies in nearby space.

Another paper maps the disc of the Milky Way by tracing weak signals seen in starlight, faint imprints of the gas and dust that floats between the stars. ̽��ֱ��Gaia team stacked six million spectra to study these signals, forming a dataset of weak features that have never been measured in such a large sample. ̽��ֱ��dataset will hopefully allow scientists to narrow down the source of these signals, which the team suspects to be a complex organic molecule. Knowing more about where this signal comes from helps us to study the physical and chemical processes active throughout our galaxy, and to understand more about the material lying between stars.

Finally, a paper characterises the dynamics of 10,000 pulsating and binary red giant stars in by far the largest such database available to date. These stars were part of a catalogue of two million variable star candidates released in Gaia DR3, and are key when calculating cosmic distances, confirming stellar characteristics, and clarifying how stars evolve throughout the cosmos. ̽��ֱ��new release provides a better understanding of how these stars change over time.

“This data release further demonstrates Gaia’s broad and fundamental value – even on topics it wasn’t initially designed to address,” said Timo Prusti, Project Scientist for Gaia at ESA.

̽��ֱ��next steps

Gaia’s previous Data Release, Gaia DR3, came on 13 June 2022. It was the most detailed survey of the Milky Way to date, and a treasure trove of data on strange ‘starquakes’, asymmetrically moving stars, stellar DNA and more. Gaia DR3 contained new and improved details for almost two billion stars in the Milky Way, and included the largest catalogues of binary stars, thousands of Solar System objects, and – more distantly and outside of our galaxy – millions of galaxies and quasars.

̽��ֱ��mission’s next Data Release, Gaia DR4, is expected not before the end of 2025. It will build upon both Gaia DR3 and this interim focused product release to further improve our understanding of the multi-dimensional Milky Way. It will refine our knowledge of stars’ colours, positions, and movements; resolve variable and multiple star systems; identify and characterise quasars and galaxies; list exoplanet candidates; and more.

Adapted from an ESA press release.

̽��ֱ��European Space Agency’s Gaia mission has released a goldmine of knowledge about our galaxy and beyond. Among other findings, the star surveyor has surpassed its planned potential to reveal half a million new and faint stars in a massive cluster, identified over 380 possible cosmic lenses, and pinpointed the positions of more than 150,000 asteroids within the Solar System.

This release represents but a small taste of the riches to be revealed with the publication of the next full release, Gaia DR4

Nicholas Walton

ESA/Gaia/DPAC

Gaia view of Omega Centauri

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

Mission to map the dark Universe sets off on space journey

sc604 — Sat, 01 Jul 2023 15:16:27 +0000

̽��ֱ��Euclid space telescope will map the 'dark Universe' by observing billions of galaxies out to 10 billion light-years, across more than a third of the sky, to gather data on how its structure has formed over its cosmic history.

Led by the European Space Agency (ESA) and a consortium of 2,000 scientists, including from the ̽��ֱ�� of Cambridge, Euclid will spend six years venturing through space with two scientific instruments: a UK-built visible imager (VIS) that will become one of the largest cameras ever sent into space, and a near-infrared spectrometer and photometer, developed in France. ̽��ֱ��mission is supported by funding from the UK Space Agency.

“Watching the launch of Euclid, I feel inspired by the years of hard work from thousands of people that go into space science missions, and the fundamental importance of discovery – how we set out to understand and explore the Universe,” said Chief Executive of the UK Space Agency, Dr Paul Bate. “ ̽��ֱ��UK Space Agency’s investment in Euclid has supported world-class science on this journey, from the development of the ground segment to the build of the crucial visible imager instrument, which will help humanity begin to uncover the mysteries of dark matter and dark energy.”

Euclid took off on board a SpaceX spacecraft from Cape Canaveral in Florida at 4.11pm (BST) on 1 July.

Cambridge’s Institute of Astronomy team has been involved in Euclid since 2010, supporting development of the astrometric calibration pipeline for the optical image data from Euclid, ensuring that the positions of the billions of sources to be imaged by Euclid can be determined to exquisite accuracy.

“Dark energy and dark matter fundamentally govern the formation and evolution of our Universe,” said Dr Nicholas Walton from the Institute of Astronomy. “ ̽��ֱ��Euclid mission will finally uncover the mysteries of how these ‘dark’ forces have shaped the cosmos that we see today, from life here on Earth, to our Sun, our Milky Way, our nearby galaxy neighbours, and the wider Universe beyond.”

̽��ֱ��Science and Technology Facilities Council (STFC) also contributed to design and development work on Euclid instrumentation and provided funding to UK astronomy teams who will analyse the data returned from the mission about the physics responsible for the observed accelerated expansion of the Universe.

“This is a fantastic example of close collaboration between scientists, engineers, technicians, and astronomers across Europe working together to tackle some of the biggest questions in science,” said Mark Thomson, Executive Chair at STFC.

UK Space Agency funding for the Euclid mission is divided between teams at ̽��ֱ�� College London, ̽��ֱ��Open ̽��ֱ��, ̽��ֱ�� of Cambridge, ̽��ֱ�� of Edinburgh, ̽��ֱ�� of Oxford, ̽��ֱ�� of Portsmouth and Durham ̽��ֱ��.

̽��ֱ��wider Euclid Consortium includes experts from 300 organisations across 13 European countries, the US, Canada and Japan.

A European mission to explore how gravity, dark energy and dark matter shaped the evolution of the Universe soared into space from Cape Canaveral on 1 July.

̽��ֱ��Euclid mission will finally uncover the mysteries of how these ‘dark’ forces have shaped the cosmos that we see today, from life here on Earth, to our Sun, our Milky Way, our nearby galaxy neighbours, and the wider Universe beyond

Nicholas Walton

ESA

Last glimpse of Euclid on Earth

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

UK-led robotic sky scanner reveals its first galactic fingerprint

sc604 — Mon, 12 Dec 2022 09:05:03 +0000

̽��ֱ��spectra provide a first glimpse of the sky from the WHT Enhanced Area Velocity Explorer (WEAVE) – a unique upgrade to the William Herschel Telescope (WHT) in La Palma on the Canary Islands.

After its integration into the WHT last year, WEAVE has now begun its on-sky commissioning phase, ready to reveal more than 12 million spectra of stars and galaxies over the next five years.

̽��ֱ��Science and Technology Facilities Council (STFC) is one of the key partners in the operation of the WHT. Data processing, analysis and archiving for WEAVE is led by astronomers from the ̽��ֱ�� of Cambridge, with support from the IAC in Spain and INAF in Italy.

Understanding the Universe through spectra

Spectroscopy is an essential element in an astronomer’s toolbox. Analysing light detected with a telescope reveals useful scientific information, such as the speed of the object observed, the atoms it is made of and its temperature.

If an image tells us what an astronomical object looks like, its spectrum tells us what it is.

First galactic spectra with WEAVE

A galactic spectrum is the combination of spectra from the millions of stars in an observed galaxy. Studying the features of a galaxy spectrum allows astronomers to understand what types of stars the galaxy contains, and the relative abundances of each type of star. This tells us about how the galaxy formed and changed over time.

First-light observations with WEAVE were carried out with the large integral-field unit (LIFU) fibre bundle, one of WEAVE's three fibre systems. ̽��ֱ��team observed the heart of the galaxy group Stephan’s Quintet, a group of five interacting galaxies.

̽��ֱ��instrument was aimed at NGC 7318a and NGC 7318b, a pair of galaxies at the centre of a major galaxy collision 280 million light-years from Earth in the constellation Pegasus.

“ ̽��ֱ��wealth of complexity revealed in this way by a single detailed observation of this pair of nearby galaxies provides insights into the interpretation of the many millions of spectra that WEAVE will obtain from galaxies in the distant Universe and provides an excellent illustration of the power and flexibility of the WEAVE facility,” said Professor Gavin Dalton from the ̽��ֱ�� of Oxford.

̽��ֱ��WEAVE LIFU (large integral-field unit) measures separate spectra for 547 different regions in and around the two galaxies, recording the colours of their light from the ultraviolet to the near-infrared.

These spectra reveal the motions of stars and gas, the chemical composition of the stars, the temperatures and densities of the gas clouds, and more. This data will help astronomers learn how galaxy collisions transform the galaxies in the group.

“Without even breaking a sweat, WEAVE has provided us with an unprecedented glimpse into the dance of this enigmatic group of galaxies,” said Dr David Murphy from Cambridge’s Institute of Astronomy, lead of spectroscopic pipeline development for WEAVE. “This exciting initial release provides a snapshot of the various ways the instrument can provide insights into the universe. Coupled with our rapid-response data-processing pipelines, WEAVE will advance cutting-edge research ranging from the complex chemical fingerprint of our galactic neighbourhood to the very structure and fabric of our universe.”

“Our advanced analysis pipeline consists of a chain of more than 20 state-of-art modules developed to analyse a wide range of astronomical targets, from newly born hot stars to quasars,” said Dr Alireza Molaeinezhad from Cambridge’s Institute of Astronomy, Lead developer of the Advanced Processing System. “Using this pipeline on the phenomenal first-light data is like wearing 3D-glasses to watch the cosmic dance of galaxies in this system.”

Eight surveys using WEAVE

In the coming five years, the ING (Isaac Newton Group of Telescopes) will assign 70% of the time available on the WHT to eight major surveys with WEAVE, selected out of those proposed by the astronomical communities of the partner countries. All these surveys require spectra of up to millions of individual stars and galaxies, a goal now obtainable thanks to WEAVE’s ability to observe almost 1000 objects at a time.

Over 500 astronomers from across Europe have organized these eight surveys, covering studies of stellar evolution, Milky Way science, galaxy evolution and cosmology. WEAVE will study galaxies near and far to learn the history of their growth, and will obtain millions of spectra of stars in the Milky Way.

“This first light event is a milestone for both the international and UK astronomy communities: WEAVE will provide spectra of millions of stars and galaxies over the next five years,” said Professor Mark Thomson, STFC Executive Chair. “After ten years in development, WEAVE will now finally offer astronomers a new eye to the sky to help them answer questions such as what is dark matter and how did stars form in distant galaxies?”

“These wonderful first light images demonstrate the power of WEAVE to unravel the intricate chemo-dynamical processes at work in this galaxy system," said Dr Nicholas Walton from the Institute of Astronomy and lead of the WEAVE data analysis system development team. " ̽��ֱ��analysis of this data, from one of the many observational modes of WEAVE, has used our state-of-the-art science pipelines. We are now ready to handle the nightly data from WEAVE as it embarks on its main science surveys."

̽��ֱ��Isaac Newton Group of Telescopes (ING) is operated on behalf of the STFC in the UK, the Nederlanse Organisatie voor Wetenschappelijk Onderzoek (NWO) in ̽��ֱ��Netherlands, and the Instituto de Astrofísica de Canarias (IAC) in Spain.

Adapted from an STFC press release.

A major telescope upgrade has peered through to the distant Universe to reveal the spectra of a pair of galaxies 280 million light years away from Earth.

Without even breaking a sweat, WEAVE has provided us with an unprecedented glimpse into the dance of this enigmatic group of galaxies

David Murphy

ING

Blue, green and red colours, according to velocities derived from the WEAVE spectra, are overlaid on a composite image of Stephan’s Quintet, featuring galaxy star light (CFH telescope), and X-ray emission of hot gas (blue vertical band, Chandra X-ray)

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

Largest chemical map of the Milky Way unveiled

sc604 — Mon, 13 Jun 2022 07:59:38 +0000

̽��ֱ��European Space Agency’s (ESA) Gaia mission has released a new treasure trove of data about our home galaxy, including stellar DNA, asymmetric motions, strange ‘starquakes’, and other fascinating insights.

Gaia: scientists take a step closer to revealing origins of our galaxy

sc604 — Thu, 03 Dec 2020 12:09:57 +0000

̽��ֱ��measurements of stellar positions, movement, brightness and colours are in the third early data release from the European Space Agency’s Gaia space observatory, and are now publicly available. Initial findings include the first optical measurement of the acceleration of the Solar system.

Launched in 2013, Gaia operates in an orbit around the so-called Lagrange 2 (L2) point, located 1.5 million kilometres behind the Earth in the direction away from the Sun. At L2 the gravitational forces between the Earth and Sun are balanced, so the spacecraft stays in stable position, allowing long-term essentially unobstructed views of the sky.

̽��ֱ��primary objective of Gaia is to measure stellar distances using the parallax method. In this case astronomers use the observatory to continuously scan the sky, measuring the apparent change in the positions of stars over time, resulting from the Earth’s movement around the Sun.

Knowing that tiny shift in the positions of stars allows their distances to be calculated. On Earth this is made more difficult by the blurring of the Earth’s atmosphere, but in space the measurements are only limited by the optics of the telescope.

Two previous releases included the positions of 1.6 billion stars. Today’s release brings the total to just under 2 billion stars, whose positions are significantly more accurate than in the earlier data. Gaia also tracks the changing brightness and the positions of the stars over time across the line of sight (their so-called proper motion), and by splitting their light into spectra, measures how fast they are moving towards or away from the Sun and assesses their chemical composition.

̽��ֱ��new data include exceptionally accurate measurements of the 300,000 stars within the closest 326 light years to the Sun. ̽��ֱ��researchers use these data to predict how the star background will change in the next 1.6 million years. They also confirm that the Solar system is accelerating in its orbit around the Galaxy.

This acceleration is gentle, and is what would be expected from a system in a circular orbit. Over a year the Sun accelerates towards the centre of the Galaxy by 7 mm per second, compared with its speed along its orbit of about 230 kilometres a second.

Gaia data additionally deconstruct the two largest companion galaxies to the Milky Way, the Small and Large Magellanic Clouds, allowing researchers to see their different stellar populations. A dramatic visualisation shows these subsets, and the bridge of stars between the two systems.

Dr Floor van Leeuwen of Cambridge’s Institute of Astronomy said: “Gaia is measuring the distances of hundreds of millions of objects that are many thousands of light years away, at an accuracy equivalent to measuring the thickness of hair at a distance of more than 2000 kilometres. These data are one of the backbones of astrophysics, allowing us to forensically analyse our stellar neighbourhood, and tackle crucial questions about the origin and future of our Galaxy.”

Gaia will continue gathering data until at least 2022, with a possible mission extension until 2025. ̽��ֱ��final data releases are expected to yield stellar positions 1.9 times as accurate as those released so far, and proper motions more than 7 times more accurate, in a catalogue of more than two billion objects.

“ ̽��ֱ��mysteries of the Milky Way and our Solar System have captured the imagination of generations of scientists and astronomers across the world – all eager to learn more about the origins of the Universe,” said Science Minister Amanda Solloway. “Through this remarkable government-backed mission, UK scientists have taken us a giant leap closer to advancing our knowledge of how our Solar System began by painting the most detailed picture yet that could help to redefine astronomy as we know it.”

Adapted from a Royal Astronomical Society press release.

An international team of astronomers, led by the ̽��ֱ�� of Cambridge, announced the most detailed ever catalogue of the stars in a huge swathe of our Milky Way galaxy.

Gaia is measuring the distances of hundreds of millions of objects that are many thousands of light years away, at an accuracy equivalent to measuring the thickness of hair at a distance of more than 2000 kilometres

Floor van Leeuwen

ESA/Gaia/DPAC; Acknowledgement: A. Moitinho.

̽��ֱ��colour of the sky from Gaia’s Early Data Release 3

Yes

Licence type:

Attribution-ShareAlike