Rubin Observatory Construction will be completed in about half a year: LSST will start before the end of 2025!

Many major milestones were accomplished in 2024, with first on-sky images obtained with an engineering camera demonstrating that the Simony Survey Telescope (SST) is operational. In early March, the main LSST camera was attached to the telescope and we anticipate the first on-sky images, the so-called First Photon milestone, in April.

Going back to the accomplishments from 2024, the primary/tertiary mirror (M1M3) for SST was coated with a layer of silver in April 2024 and thus prepared for final integration with the rest of the telescope.  The last major piece of equipment, the LSST Camera, was shipped from SLAC to Chile in May 2024. The successful transport of the camera and supporting equipment and tools, (3 large containers and 47 crates) to Chile, first by Boeing 747 plane from San Francisco to Santiago and then by 9 trucks to the Observatory, was a major step towards the completion of the Rubin Observatory. 

Rubin’s Simony Survey Telescope was fully integrated for the first time in early October 2024, with all three mirrors and an engineering (commissioning) camera installed. After 10 years of intensive construction of the Rubin Observatory, and 20 years since the project began, the first images of the night sky were obtained with engineering camera on October 24, 2024! In parallel with hardware integration and commissioning, software pipelines are being completed and tested using extant and Rubin Auxiliary Telescope data, as well as these commissioning image data. In particular, the Rubin group at DiRAC is leading the Alert Pipeline testing and commissioning. 

After using this telescope configuration to image the sky until mid-December 2024, the Rubin team removed the 144-megapixel engineering camera and installed the final science component: the car-sized 3,200-megapixel LSST camera. We except the very first on-sky images with the LSST Camera in April, the first science quality images by early summer, the completion of the construction project by the end of September, and the start of 10-year Legacy Survey of Space and Time before the end of 2025.

As Rubin Observatory Construction is nearing its completion, the Rubin Operations Team is preparing for the start of LSST and relentless sky surveying, while several thousand members of eight Rubin Science Collaborations are finalizing their preparations and tools for data analysis. DiRAC’s members are playing a major role in these preparations and positioning themselves to partake in the rich harvest of science results to be soon enabled by LSST data!

Prof. Željko Ivezić

Director of Rubin Construction

Professor of Astronomy, University of Washington

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By Suberlak, Crenshaw, Kalmbach, Connolly

The Vera Rubin Observatory recently completed an extensive testing run using its engineering test camera (ComCam), marking a significant milestone toward full operations. Beginning as a dream in 1998, and under construction since 2015, this exciting moment marks the first time Rubin has observed the night sky. This crucial seven-week testing phase, which ran from late October to mid-December 2024, utilized ComCam—a smaller version containing just nine of the 189 CCD sensors that will be present in the final 3.2-gigapixel LSST Camera.

Members of the DiRAC Institute—Andrew Connolly, John Franklin Crenshaw, Bryce Kalmbach, and Chris Suberlak—played a central role in the testing, working on-site in Chile throughout the session. Their work focused primarily on Rubin’s Active Optics System (AOS), which maintains optimal image quality across the telescope’s 9.6 deg² field of view by analyzing wavefront sensor data in real-time, calculating necessary adjustments, and controlling the positioning actuators on the primary and secondary mirrors despite environmental challenges like temperature fluctuations and mechanical stress. Successful operation of this complex system is necessary for Rubin to achieve its lofty science goals.

“35 out of the 52 nights of the engineering run featured at least one of the DiRAC team members on the summit. During one of the observing nights, Suberlak gave a quick online tour of the summit control room, answering questions via livestream for DiRAC guests gathered at the UW Planetarium. Much of the night’s work focused on implementing and testing new control software settings and evaluating how pipeline improvements affected image quality. These tests required close collaboration between AOS test scientists, observing specialists, and other team members, who provided rapid feedback to debug software and hardware issues.

No two nights felt dull or repetitive. One evening, a series of images revealed an unusual light pattern—something the team had never seen before. After two trips to the telescope dome, they discovered the culprit: a light source beneath the main 8.2 m mirror (M1/M3) had been left on due to a low-level software bug. On another occasion, thick clouds covered nearly the entire sky, and the weather forecast predicted slim chances of capturing useful images. Yet, as the night progressed, the sky unexpectedly cleared. Not only did the team manage
to take images, but the quality exceeded expectations—better than on many other nights—thanks in part to the AOS feedback loop.

We eagerly anticipate what the commissioning of the LSST Camera (LsstCam) will bring!

Nora Shipp, UW assistant professor of astronomy, was part of one of eight interdisciplinary teams awarded the Collaborative Innovation Award in the first year of Scialog: Early Science with the LSST.

This initiative, launched by the Research Corporation for Science Advancement, is a three-year program designed to support early-career scientists as they prepare to utilize data from the upcoming Legacy Survey of Space and Time, or LSST, at the Vera C. Rubin Observatory in Chile.

“Scialog has been a great opportunity to make connections with scientists across the field of astronomy to brainstorm new ideas for taking advantage of the unprecedented data that will soon be provided by the LLST ,” said Shipp.

Shipp’s proposal brings together researchers to study stars and dark matter — not just in the Milky Way, but also in smaller galaxies. By using the LSST to reveal the faint outer regions of these galaxies, the research will help us to better understand the universe’s creation and the limits of how galaxies form.

Scialog, which is short for “science + dialog, “is a collaborative program launched by RCSA in 2010. It’s designed to accelerate breakthroughs by fostering a network of creative scientists across disciplines and encouraging intensive discussions on scientific themes of global importance.

As part of this initiative, the conference brought together an expert group of scientists and facilitators, including Eric Bellm, research assocaite professor of astronomy and   DiRAC Institute Fellow, to guide the discussions.

By Victoria T. Tyron, University of Washington

At DiRAC Institute, we are fortunate to have a talented group of astronomers whose work is expanding our understanding of the universe. From exploring the outer solar system and developing algorithms for asteroid impact prevention to advocating for cleaner skies and advancing the search for asteroids, their research is making significant contributions to the field of astronomy. We’re excited to share a glimpse into their work and the unique projects they’re leading, brought to you by the dedicated team of journalists from the UW News Lab: Amelia Kim, Dany Villarreal, Cassie Diamond, Pei Xu and Cameron Delfin.

Here are a few profiles of our researchers, showcasing their areas of expertise and contributions to the field.

Click on the links to read their stories.

Sarah Greenstreet’s Journey in Making New Discoveries with the Rubin Observatory

Joachim Moeyens: UW Researcher’s Algorithm Enables Asteroid Impact Prevention

Astronomer Ari Heinze and the Search for Asteroids

Meredith L. Rawls: Research Scientist for Vera C. Rubin Observatory Fighting for Cleaner Skies

Pedro Bernardinelli Explores the Outer Solar System at the Rubin Observatory in Search of New Discoveries

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Welcome back to campus as we embark on a new academic year! I hope you all had a great summer and are ready to dive into your studies and research.

This summer was a vibrant time for the DiRAC community, marked by significant research endeavors. I’m excited to highlight some of this research: Aritra Ghosh’s groundbreaking paper, published in August, explores the fascinating relationship between galaxies in dense environments and the effects of their surroundings. Using machine learning techniques, Aritra analyzed 3 million galaxies observed by the Subaru telescope and conclusively showed that galaxies with many neighbors are larger than their more isolated counterparts — an observational result that contradicts current theoretical expectations. If you haven’t had a chance to read it yet, I highly encourage you to do so!

Additionally, I’m thrilled to welcome our new DiRAC members who have joined us this quarter: Prof. Nora Shipp, Astronomy Assistant Professor and new addition to the DiRAC Faculty; Dr. Peter Ferguson, the 2024 DiRAC Postdoctoral Fellow; Dr. Arpit Arora, a postdoc studying galactic dynamics and dark matter; and Michael Tauraso, Software Engineer with the LINCC Frameworks. They bring a diverse set of interests and skills to our team, just in time for LSST. With Nora, Arpit, and Peter joining us, I look forward to DiRAC playing a major role in near-field cosmology in the upcoming years.

As always, we’re striving to make this academic year a productive and inspiring one, filled with learning and discovery. But this year will be special: after nearly two decades of R&D and construction, the Rubin Observatory is entering its commissioning phase in early November and will begin the largest survey of the universe in mid-2025. Expect to read more about it on these pages over the next few months, as the first data starts to arrive.

Welcome to the year of discovery, and follow us as we strive to understand the universe!

Warm regards,

Mario Juric

DiRAC Director

UW Be Boundless Campaign featured Professor Mario Jurić and his undergraduate students, showcasing how to use cutting-edge coding skills to help scientists make the most of discoveries from a revolutionary Vera C. Rubin Observatory’s telescope.

The Rubin Observatory, in northern Chile, will begin a 10-year survey of the night sky in 2025. It is an example of how to harness new technology to drive discoveries and cultivate a new generation of innovators. 

Every night, the Rubin’s Simonyi Survey Telescope will capture millions of changes in stars and other objects. This database of the night sky will require algorithms to sift through the billions of bits of information, so DiRAC scientists and engineers are already crafting the software. And that’s where the future astronomers in Jurić’s class come in.

Read the full article here.

At the University of Washington Peter Ferguson is a DiRAC postdoctoral fellow as well as a fellow in the eScience institute. Previously, he was a postdoc at the University of Wisconsin-Madison, where he was part of the observational cosmology group, and he completed his PhD at Texas A&M University.

Peter Ferguson is interested in learning about the nature of dark matter and galaxy formation using wide-field astronomical surveys such as the Legacy Survey of Space and Time (LSST) at the Vera C. Rubin Observatory.

In particular, he works on finding and characterizing stellar streams and dwarf galaxies in the local universe and enabling this science by making infrastructure level contributions to cosmological surveys. These contributions range from instrumentation and calibration to science validation and software development.

In a new paper published in The Astrophysical Journal, the team, which used a machine-learning algorithm to analyze millions of galaxies, reports that galaxies found in denser regions of the universe are as much as 25% larger than isolated galaxies. The findings resolve a long-standing debate among astrophysicists over the relationship between a galaxy’s size and its environment, but also raise new questions about how galaxies form and evolve over billions of years.

Dr. Aritra Ghosh, a UW postdoctoral researcher in astronomy and an LSST-DA Catalyst Fellow with the UW’s DiRAC Institute, led the team behind this discovery, which includes researchers at Yale, the Leibniz Institute and Waseda University. Dr. Andrew Connolly, a UW professor of astronomy, is co-author on the study.

Here is a link to the full story written by James Urton for the UW News.

https://www.washington.edu/news/2024/08/14/galaxy-size/