Thanks to the generous support of the DiRAC Advisory Board, and the local UW Astronomy community, the Student Research Prize Program was successfully wrapped up for 2023 this August!

Now in its second year, this prize supports undergraduate research in astronomy at the University of Washington, providing students a stipend to focus on their independent research projects under the supervision of UW faculty and scientists. Previous winners of this prize have presented at local and national research conferences, contributed to peer-reviewed publications, and continued on to graduate school. Our summer program has also been featured in the UW College of Arts and Sciences’ Newsletter.

This year we are excited to award 5 summer prizes, including students across a wide range of astronomy and astrophysics research topics:

• Katelyn Ebert (Advisor: Prof. Matt McQuinn): Precision Measurement of the Hubble Constant with Fast Radio Bursts
• John Delker (Advisor: Prof. Andy Connolly): Classifying Transients with ParSNIP
• Celeste Hagee (Advisors: Andy Tzanidakis and Prof. James Davenport): Building a Data-Driven Calibration Model for the Gaia BP/RP Epochal Spectra Using Supernovae
• Bowang Lan (Advisors: Jake Kurlander and Prof. Mario Juric): Investigations with HelioLinC
• Benjamin Herrera (Advisor: Prof. Sarah Tuttle): MARVIN Optimization for Generalized IFU Use

Thank you to the generous community that supports truly excellent student research at the University of Washington, especially our principle donors David Brooks and Jeff Glickman. You are helping the next generation of scholars to build the most advanced datasets, algorithms, and tools to explore and understand the universe!

The Vera Rubin Observatory, currently being completed amid the beautiful desolation of the Chilean Andes, is scheduled to begin the most ambitious survey yet of the night sky. Starting in 2025, Rubin will make precise measurements of an estimated forty billion stars and galaxies, most currently unknown. Over ten years of planned operations, Rubin will produce 60 petabytes of data — mapping more than half the sky at a level of detail previously achieved only over small regions.

Rubin is also intended to help protect the earth by discovering thousands of potentially hazardous asteroids too faint for smaller telescopes to detect. In order to survey the cosmos with maximal efficiency, Rubin will take only two images of each patch of sky every night — while currently operating asteroid surveys take four images. Four images are needed to make sure a candidate asteroid is actually real. With only two or three sightings, an asteroid candidate is too likely to be a coincidence of glints from stars or other ‘image junk’, rather than a real object.

Using new algorithms, though, Rubin will be able to combine data from multiple nights, identifying which candidate detections must be real because they line up along a consistent orbital trajectory from night to night. Rubin’s algorithm of choice is based on HelioLinC, invented in 2018 by Smithsonian senior astrophysicist Matt Holman. At the University of Washington, Siegfried Eggl (now a professor at the University of Illinois) and I (Ari Heinze) developed a new version called HelioLinc3D, which uses orbital physics to sort through millions of junk detections and find the real asteroids moving in a consistent way.

HelioLinc3D works great in simulations, but can it discover dangerous near-Earth objects (NEOs) in real life? The most definitive demonstration would be discovering a new NEO in real data from an existing survey — and John Tonry and Larry Denneau, who lead the Hawaii-based ATLAS survey, offered ATLAS data for a test.
To make an actual discovery, HelioLinc3D would have to find something the regular ATLAS software missed — and it doesn’t miss much. I searched archival ATLAS data with HelioLinc3D for weeks, but every NEO I found had been discovered long before. Finally, though, HelioLinc3D flagged the asteroid now designated 2022 SF289. ATLAS had detected this NEO on four different nights — but the object was so faint that it was sighted in only three images on each night — never the four detections required for a single-night discovery. Only a multi-night linking algorithm such as HelioLinc3D could combine the tenuous detections to prove the object was real: the very first NEO ever discovered with the new algorithm.

Like other surveys, ATLAS makes millions of candidate asteroid detections every night — thousands even in the small patch of sky shown here. The power of HelioLinc3D is its ability to handle the mathematical complexity of an astrophysical ‘connect the dots’ game in situations like this, where we’re pushing hard to attain sensitivity to the faintest objects and necessarily picking up a lot of ‘image junk’ in the process. In the plot above, four circles highlight the detections of 2022 SF289. In each circle is a tiny string of three overlapping dots — three real detections that look superficially identical to thousands of ‘junk’ detections in the same plot. The fact that measurements from all four nights lie precisely along a consistent orbit — far more precisely than could reasonably occur through random chance — is what proves that the discovery is real.

Only a sophisticated mathematical algorithm like HelioLinc3D could prove that those sets of barely-detectable glimmers all correspond to a single giant rock hurtling through space.
Once the ATLAS observations identified by HelioLinc3D constrained the orbit of 2022 SF289, we knew where to look for some additional detections. Joachim Moeyens, also a researcher at the University of Washington and the B612 Foundation’s Asteroid Institute, identified three images from Caltech’s Zwicky Transient Facility. The Minor Planet Center, the global clearinghouse to which all asteroid discoveries are submitted, identified additional detections from the Hawaii-based Pan-STARRS survey nearly two weeks after the first ATLAS measurements, and later still from the Catalina Sky Survey’s Mt. Lemmon telescope. These additional detections refine our knowledge of 2022 SF289’s orbit and further confirm its reality.

It turns out that 2022 SF289 isn’t just a near-Earth asteroid, it’s a particularly large one (estimated diameter 600 feet) that comes close enough to Earth to be officially designated as a potentially hazardous asteroid, one of about 2350 currently known. It comes within 190,000 miles — less than the distance to the moon — of Earth’s orbit, but 2022 SF289 won’t impact Earth in the foreseeable future. That’s a good thing, since it would explode violently enough to destroy multiple cities if it struck a populated area. The discovery of 2022 SF289 proves that HelioLinc3D can discover potentially hazardous asteroids — not just in simulations but in the real Universe. It’s the strongest possible demonstration that the Vera Rubin Observatory will fulfill its promise of discovering and tracking thousands of new potentially hazardous asteroids. 2022 SF289’s discovery represents another step forward in the ongoing, global effort to defend our planetary home — and even though we call it a potentially hazardous asteroid, the fact that we found it should make us all feel safer.

Written by Ari Heinze

Related Press:

James Urton, UW News – New algorithm ensnares its first ‘potentially hazardous’ asteroid

Robin George Andrews, New York Times – Killer Asteroid-Spotting Software Could Help Save the World

BY JAMIE SWENSON | PHOTO BY BRUNO C. QUINT, RUBIN OBSERVATORY

Earlier this month, a beautiful print issue of the UW Magazine featured DiRAC. Here is the article in the digital format.

Related article:

UW Story, Secrets of the Stars

Welcome to the June edition of DiRAC’s newsletter!

As the academic year ends, we have an exciting lineup of updates to share with you, showcasing the achievements and outreach made by our excellent team members.

In March, our researchers had the privilege of sharing their groundbreaking discoveries at the captivating DiRAC Planetarium Event, showcasing our work ranging from astronomical software to mapping where water is in the solar system. Here, we give you a flavor of that work: a captivating research highlight from Bryce Kalmbach, DiRAC research scientist, and Harish Krishnakumar, a high school student from Tesla STEM high school in Redmond, showcasing their work on detecting rare ring galaxies using deep learning.

The anticipation of science from Rubin Observatory has also been a feature story on UW’s main website this past May.

Finally, we extend our heartfelt gratitude for your incredible support on Husky Giving Day. Your support enables us to continue the Summer Research Prizes for UW graduate and undergraduate students, for some of whom this is their first foray into astronomy.

So, grab a cup of coffee, sit back, and join us on this cosmic journey as we delve into the awe-inspiring world of astronomy.

Thank you,

Mario Juric
Director, DiRAC Institute
Professor, Department of Astronomy

On March 1st, 2023 DiRAC hosted the first of a series of events “A New Era of Discovery: Mapping the Universe with the Rubin Observatory” at the UW Planetarium.

The interest in the event exceeded all the expectations. The evening was planned around two planetarium shows and many opportunities to hear the latest updates from scientists, postdoctoral fellows, engineers, and students – all contributing in building the largest sky survey in human history.

UW astronomers informed and engaged guests in various topics from the Rubin Alert Distribution System, Asteroid Dynamics & Impacts to the Big Data & Citizen Science.

In the second part of the evening, DiRAC Director, Prof. Mario Juric, acknowledged one of the major donors and a partner, B612 Foundation. He presented Danica Remy, B612 President, with a small token of gratitude after which a former astronaut and the Asteroid Institute Executive Director, Ed Lu, joined the conversation virtually on Zoom.

DiRAC team is energized by the support of its community and plans to continue the momentum of excitement and curiosity especially as we are nearing the Rubin Observatory’s first light in 2024. We will share the knowledge as we learn it and present opportunities to further engagements and events.

If you would like to stay in touch and learn about the next event, please email us at dirac@uw.edu

“A New Era of Discovery: Mapping the Universe with the Rubin Observatory”

We’re at the brink of a new age of survey-driven discovery in astronomy. Where before we could only study a handful of objects at a time, new detectors, algorithms, and telescopes will soon allow us – and the entire world – to monitor billions.

The flagship of this era will be the Rubin Observatory, set to open in Chile in late 2024. Rubin will continuously gather data for over 20Bn stars, 20Bn galaxies, with billions of asteroid observations. In importance, it is a ground-based peer of the Webb space telescope.

In about a year, DiRAC researchers, students, and citizen scientists will use Rubin to scan the Solar System for hazardous asteroids, discover interstellar comets, and search for new planets in our Solar System. Our codes will map the Milky Way, detect the most energetic explosions in the universe, and help understand Dark Energy. Our students will learn about astronomy by participating in once-in-a-generation wave of discovery.

We’re looking forward to sharing this with the community of enthusiasts, friends, and supporters who make DiRAC possible. 

For more upcoming events check out our website’s news and events page.

On April 6, 2023, DiRAC and UW Astronomy participated in the annual Husky Giving Day event. It was another successful drive for support of our student research programs, with more than 20 individual donors raising a total of over $15,000!

We would like to especially recognize the contributions of members of the DiRAC Advisory Board, particularly David Brooks and Jeff Glickman, who have once again been instrumental at supporting this program. We are currently in the process of awarding these 2023 summer research prizes, and we can’t wait to see what amazing research our students pursue.

Last year we were able to launch successful Summer Research Prize program for undergraduates, which was recently profiled by the UW College of Arts and Sciences Newsletter. This year we were aiming to continue the summer undergraduate prize, as well as kick off a new graduate student support program!

This kind of community-driven support is critical for the programs at DiRAC and UW Astronomy. We have one of the largest undergraduate astronomy programs in the nation, and a world-class cohort of graduate students. If you would like to support the work of these amazing young scientists at any level, please consider making a gift!

In Fall 2021, Harish Krishnakumar, then a junior at Tesla STEM high school in nearby Redmond, Washington, reached out to DiRAC Research Scientist Bryce Kalmbach to be his research mentor for a science fair project detecting and studying the properties of ring galaxies in large extragalactic galaxy surveys. Harish’s work eventually took him to the 2022 Regeneron International Science and Engineering Fair where he won two special awards during the competition.

Recently, Harish and Bryce have been working on a paper summarizing their work that has been submitted to the Astronomical Journal and is available on the ArXiv: https://arxiv.org/pdf/2210.11428.pdf.

The work presented in the paper uses convolutional neural networks (CNNs) to identify ring galaxies in postage stamp cutouts of galaxies from the Pan-Starrs 1 survey. CNNs are a commonly used deep learning method for classifying objects in large data sets of images. Since ring galaxies are a rare type of galaxy, one of the challenges of this work was finding enough ring galaxies to train the CNNs. For this, the authors turned to the Galaxy Zoo project which used human volunteers over many months to manually classify galaxy morphological types in images. They also used a technique called transfer learning where the neural networks were trained on a larger set of simulated galaxies before parts of the network were retrained on real data. Understanding and applying computational methods such as CNNs will be necessary to detect ring galaxies and other rare galaxy morphologies in the data provided by existing and future surveys like the Vera Rubin Observatory’s Legacy Survey of Space and Time (LSST). In the end, Harish and Bryce identified 1,151 new ring galaxies after examining over 900,000 galaxies in 10 hours of computation time showcasing a powerful new technique for finding rare morphologies of galaxies in large galaxy surveys.