Meet the Team: LINCC Project: Doug Branton

Doug Branton is a Software Engineer for the LINCC project located at the University of Washington. Doug completed his undergraduate studies in Physics and Astronomy at the University of Washington, and afterwards worked at the Space Telescope Science Institute for five years, where he supported the Hubble Space Telescope as a member of the Space Telescope Imaging Spectrograph (STIS) team. His research interests include the application of data science, machine learning, and software engineering to solve data-intensive challenges in Astronomy, particularly those that come along with survey-scale datasets.

https://github.com/dougbrn [github.com]

Mysterious ‘twilight’ asteroids

Some rare asteroids are only visible to telescopes during the few short hours during morning and evening twilight, making them notoriously difficult to discover.

In her leadership role within the LSST’s Solar System Science Collaboration, Sarah Greenstreet has led recent efforts to ensure that LSST uses a portion of the survey to search the twilight near-Sun sky for these elusive asteroids. This would give LSST the potential to vastly increase the number of known asteroids in the near-Sun population, allowing us to study these objects on both a deeper and broader level than ever before.

In July 2022, Sarah Greenstreet’s research over the past decade on the population of asteroids that live very close to the Sun was featured in a National Geographic article that highlighted her current research, including an article Sarah wrote for Physics Today last year.

Here we bring a short excerpt; read full article in the National Geographic.

PHOTOGRAPH BY DOEFNALDECAMR. HAHNCTIONOIRLABAURANSF

“Spotted in early 2020, ꞌAylóꞌchaxnim is just shy of a mile wide—big enough to pack a painful punch if it ever smashes into a planet. Which, astronomers say, it probably will.

“It’s most likely going to hit Venus in the future,” says the University of Washington’s Sarah Greenstreet, who modelled a future for ꞌAylóꞌchaxnim as part of her studies of the origins and fates of these inner asteroids.

According to Greenstreet’s models, as well as others, the most likely scenario is for ꞌAylóꞌchaxnim to get tangled up with Venus sometime in the next several million years. As it zips around the sun, the rocky body is being jiggled by the gravity of Mercury and by sunlight itself, both of which can perturb its orbit, gently pushing it outward and onto a collision course with Earth’s hellish sister world.”

….

Read full article in the National Geographic.

Searching the SETI Ellipsoid with Gaia

In September 2022, James Davenport and his colleagues published a research paper “Searching the SETI Ellipsoid with Gaia”.

The “SETI ellipsoid” is an egg-shaped zone of space where alien civilizations would have had enough time to observe an astronomical event (in this case, the SN 1987A supernova blast) and then send out a signal that could be observed from Earth. Click on the image for a larger version. (Davenport et al. via Arxiv)

The search for extraterrestrial intelligence (SETI) Ellipsoid is a geometric method for prioritizing technosignature observations based on the strategy of receiving signals synchronized to conspicuous astronomical events. Precise distances to nearby stars from Gaia makes constraining Ellipsoid crossing times possible. Here he and his colleges explore the utility of using the Gaia Catalog of Nearby Stars to select targets on the SN 1987A SETI Ellipsoid, as well as the Ellipsoids defined by 278 classical novae. Less than 8% of stars within the 100 pc sample are inside the SN 1987A SETI Ellipsoid, meaning the vast majority of nearby stars are still viable targets for monitoring over time. They find an average of 734 stars per year within the 100 pc volume will intersect the Ellipsoid from SN 1987A, with ~10% of those having distance uncertainties from Gaia better than 0.1 lyr.

GeekWire picked up the story, you can read the full article here, and watch Jim’s talk at the Astronomy on Tap here.

Letter From the Director

Welcome to the DiRAC Institute Spring newsletter!

As we’re nearing the close of this academic year, I’m excited to share with you some of the work, discoveries, teaching and mentoring initiatives started at DiRAC over the past months.

Today, the New York Times features the discovery of 104 asteroids by the Asteroid Institute, using the THOR algorithm running on the Asteroid Discovery Analysis and Mapping (ADAM) cloud-based astrodynamics platform! This groundbreaking computational technique running ADAM not only allows us to discover and track asteroids in historical data sets, but will change the way we do asteroid discovery in the future.  

We would like to announce the DiRAC Research Prize for Undergraduate Research, a new paid summer research opportunity for UW undergraduates. This program will enable UW students to spend a quarter with DiRAC researchers working on data-intensive problems across all areas of astrophysics. Such hands-on experiences offer opportunities to further develop research skills and understand how research works in practice from idea to an academic poster or paper. This Prize was made possible by generous funding received from DiRAC Husky Giving Day 2022 supporters and the DiRAC Advisory Board.

Beyond the Prize, we are also happy to be supporting the return to in-person of “Astronomy on Tap” — a UW graduate-student driven outreach program — and share a few research highlights from the multitude of amazing research at the Institute: from discovering rare “black widow” binary star, protecting the view of the heavens from satellite constellations, to supernova siblings discovered in the ZTF survey.

These are just some of the many accomplishments our researchers made in a year still marked by the lingering impacts of the pandemic. I am extremely proud by how all of us — our staff, our undergraduate and graduate students, postdocs, researchers, engineers and faculty — who continue to be supportive and caring for each other, while expanding the boundaries of science.

Thank you,

Mario Jurić

Director, DiRAC Institute
Professor, Department of Astronomy

New Summer Research Prize for UW Students

We are pleased to officially announce our new Summer Research Prize for UW undergrads!

This program will award $3500 to UW undergrads working on summer projects with researchers in the DiRAC Institute (note: we especially welcome projects w/ collaborative mentors across the department!). 

Thanks to the generous support from the Advisory Board members and the community during Husky Giving Day, we expect to award 5 of these prizes this summer.

The application form is simple, and can be turned in via email to jrad@uw.edu. Selections will be made before the end of Spring Quarter. Prize winners will give a brief seminar at the end of the Summer or early Fall to showcase their projects, which the entire department will be invited to.

University of Washington

Astronomy on Tap is Back

After a long time, and many breaks, hiatuses, and Astronomy’s at Home, for the first time in two years AoT is back in person! It resumed in February and be sure to follow them on Twitter and Facebook to get updates on future events or watch past events on their YouTube channel.

Each FREE Astronomy on Tap event features accessible, engaging science presentations on topics ranging from planets to black holes to the beginning of the Universe. Most events have games and prizes to test and reward your new-found knowledge! There is always lots of time to ask questions and interact with the presenters and other scientists who inevitably stick around for the beer.

Supernova Siblings and their Parent Galaxies in the ZTF Bright Transient Survey

Supernovae are the explosions of stars that can be seen across vast distances, appearing as new bright points of light in optical images of the sky, even when the original star was far too faint to be detected.

When different types of stars explode (e.g., low-mass and high-mass) they cause supernovae with a variety of characteristics (e.g., brightness, color, duration). When two or more supernovae (explosions of stars) occur in the same galaxy, we say they have the same “parent galaxy” and are “sibling supernovae”. The characteristics of sibling supernovae can thus be compared knowing that, since they have the same distance from Earth and come from similar environments, any differences between them are more likely to be related to the type of star that exploded. Sibling supernovae are thus very useful for obtaining a better understanding of both supernovae and their parent galaxies.

“An image of the grand design spiral galaxy Messier 100, which has parented at least seven sibling supernovae in the past century (that we know of!). This image was obtained through the g filter by the PanSTARRS survey, and siblings 2019ehk and 2020oi were discovered by ZTF.”

Since the average supernova rate for a Milky Way-type galaxy is just one per century, a large imaging survey is required to discover an appreciable sample of sibling supernovae. In this paper we present 10 sibling supernovae in 5 parent galaxies from the wide-field Zwicky Transient Facility (ZTF).

For each of these families we analyze the supernova’s location within the parent galaxy, finding agreement with expectations that supernovae from more massive stars are found nearer to their parent galaxy’s core, and in regions of more active star formation.

We also present an analysis of the relative rates of core collapse and thermonuclear sibling supernovae, finding a significantly lower ratio than past samples due to the unbiased nature of the ZTF.

Published paper by Melissa Graham

ADS: Supernova Siblings and their Parent Galaxies in the Zwicky Transient Facility Bright Transient Survey

About

Melissa Graham currently works for Rubin Observatory as the Lead Community Scientist for the Community Engagement Team and as a Science Analyst for the Data Management team. Her main research focus is supernovae, especially those of Type Ia.

Astronomers Discover a Rare ’Black Widow’ Binary, With the Shortest Orbit Yet

The flashing of a nearby star drew the attention of a team of astronomers, who discovered that it is part of a rare and mysterious system. As they report in a paper published May 4 in Nature, the stellar oddity appears to be a “black widow binary” — a type of system consisting of a rapidly spinning neutron star, or pulsar, that is circling and slowly consuming a smaller companion star, as its arachnid namesake does to its mate.

The team, led by co-author Kevin Burdge, a postdoctoral researcher at the Massachusetts Institute of Technology, found the black widow binary utilizing data from the Zwicky Transient Facility, a California-based observatory that takes wide-field images of the night sky.

“This discovery highlights the potential of large time-domain surveys like ZTF to find rare astrophysical objects,” said co-author Eric Bellm, a research assistant professor of astronomy at the University of Washington, fellow at the UW’s DiRAC Institute and scientist with both the ZTF and the Chile-based Vera C. Rubin Observatory.

Read full UW Press Release here.

An illustrated view of a black widow pulsar and its stellar companion. The pulsar’s gamma-ray emissions (magenta) strongly heat the facing side of the star (orange). The pulsar is gradually evaporating its partner.NASA/Goddard Space Flight Center/Cruz deWilde

Heavens Need Environmental Protection Just Like Earth, Experts Say

Space urgently needs special legal protection similar to that given to land, sea and atmosphere to protect its fragile environment, argues a team of scientists. The scientific, economic and cultural benefits of space should be considered against the damaging environmental impacts posed by an influx of space debris — roughly 60 miles above Earth’s surface — fueled by the rapid growth of so-called satellite mega-constellations.

In a paper published April 22 in Nature Astronomy, the authors assert that space is an important environment to preserve on behalf of professional astronomers, amateur stargazers and Indigenous peoples.

“We need all hands on deck to address the rapidly changing satellite situation if we can hope to co-create a future with dark and quiet skies for everyone,” said co-author Meredith Rawls, a research scientist with the Vera C. Rubin Observatory and the University of Washington’s Data Intensive Research in Astrophysics and Cosmology Institute, or DiRAC Institute.

Read UW News article in full here.

Starlink satellites over the Carson National Forest in New Mexico, photographed shortly after launch.M. Lewinsky

Letter From the Director

Welcome to the DiRAC Institute newsletter, winter edition!

One quarter into the new academic year, I’m excited to share with you new additions to DiRAC’s team, and some of the exciting work and discoveries made by our researchers.

We are very pleased to welcome two new DiRAC Postdoctoral Fellows, Azalee Bostroem and Pedro Bernardinelli. Azalee brings us the exciting world of supernovae research and applications of data science in astronomy, whereas Pedro’s work takes us to the outskirts of the Solar System in search of new (dwarf) planets and comets. You can read more about their research in this newsletter.

Read further about remarkable new machine-learning driven “supernova recognizer” by Kyle Boon. In his recently published paper Kyle introduced a new statistical model called ParSNIP, which can be distinguish different types of supernovae significantly better than other state-of-the-art methods. Kyle’s code is open source, ready to be used by researchers in the community.

Finally, we will tell you about a major, multi-year collaboration we started with Carnegie Mellon on astronomical software for LSST, co-led by our Prof. Andy Connolly and generously funded by Schmidt Futures. Through this work, a team of a dozen software engineers and scientists will work to create new software platforms to analyze extremely large astronomical datasets. These types of systems will allow us to truly harness the data from the upcoming Legacy Survey of Space and Time, and map and understand the structure of our Universe.

Mario Jurić

Director, DiRAC Institute
Professor, Department of Astronomy