Astronomy on Tap is Back

Join DiRAC’s research team, Meredith Rawls and Jim Davenport, as Astronomy on Tap returns to its original location in the newly opened Bickersons Brewhouse in Ballard on May 25th at 8pm.

UW Space Dialogue with Meredith Rawls

Astronomy, satellites, and the future of our sky

Join us Thursday, May 5th at Noon PDT on Zoom

We are witnessing a new era as skies fill with thousands of low-Earth-orbit satellites that reflect sunlight. Observational astronomy at all wavelengths is increasingly affected, and so is the shared human experience of the night sky. For optical ground-based astronomy, the impacts of satellites are worst for large wide-field facilities. One urgent example is Rubin Observatory in Chile, which will begin a ten-year sky survey in 2024. I will discuss how satellite streaks can impede discovery, and share recent studies that aim to better quantify this. Finally, I will describe the work underway by a dedicated international team to understand, disseminate, and mitigate the impacts across the electromagnetic spectrum for increasingly broad groups of stakeholders.

Meredith Rawls is a research scientist in the Department of Astronomy and DiRAC Institute at UW. She writes software and data pipelines to handle terabytes of nightly images from Vera C. Rubin Observatory’s Legacy Survey of Space and Time, which will produce the highest resolution movie of the night sky ever made. Her background is in stellar astrophysics, and she earned her PhD from New Mexico State University. Lately she studies the plethora of newly-launched commercial satellites in the hopes observers worldwide don’t lose the sky. She has served on and chaired working groups and coauthored reports for numerous astronomy workshops on satellite constellations, and she is spearheading the SatHub initiative at the new International Astronomical Union Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference.

Seattle Science Slam

After a 2 year hiatus, we’re back, and will be resuming our monthly events through fall.

Next event is on May 11th at 8pm. Seattle Science Slam is a free event featuring three engaging and accessible presentations from scientists. The audience’s applause decides who wins. This month we have an astrophysics talk on the fate of our sun, a statistics talk about mosquitos and west nile virus, and a chemical engineering talk on drug delivery. 

Kids friendly, dog friendly, arrive early to get seats. Outside food allowed, food truck on-site. Be sure to follow us on Facebook or subscribe to our email list to get updates on future events!

Astronomy on Tap Tonight

Astronomy on Tap returns to Bad Jimmy’s tonight at 8pm!

Come out and support Astronomy department members Azalee Bostroem and Megan Gialluca as they tell us about supernovas and aliens!

The event is outdoors and the patio is covered and heated, but if you can’t make it in person you can also participate from the comfort of your home via our livestream!

There are several food options nearby, and you’re welcome to bring food into the brewery. Hope to you can join us!

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 w/ researchers in the DiRAC Institute (note: we especially welcome projects w/ collaborative mentors across the department!). 

Thanks to the generous support from the community during Husky Giving Day, we expect to award 4 or 5 of these prizes this summer.

The application form is simple, and can be turned in via email to 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.

Apply here.

Space Grant Summer Research – Apply now!

Washington state’s NASA Space Grant program at the UW invites you, as a faculty member conducting research in a STEM area, to participate our 2022 Summer Undergraduate Research Program (SURP).  The application period for students closes on Friday, April 8, 2022.

SURP is an excellent way to extend your summer funding through WA Space Grant’s contribution of half of the selected student’s award payment.  Faculty contribution per student is $2,750 full-time and $1,375 part-time.

If you already have a student working with you, we encourage you to apply for the program along with that student.  If you are looking for new students, you can apply and we will help to match you with a qualified undergraduate.

Through SURP, WA Space Grant seeks to increase research opportunities for undergraduates on NASA-related STEM projects, and we particularly welcome applications from students with traditionally marginalized genders and from underrepresented minoritized communities.  UW undergraduate students in good academic standing who are interested in research in science, technology, engineering or mathematics fields are eligible to apply. Applicants must be U.S. citizens.

The faculty request form is available at

The student application is also open through April 8, 2022.  Information for students can be found at:

Simulated SPHEREx spectra of asteroids and their implications for asteroid size and reflectance estimation

In January 2022, published paper by Zeljko Ivezić, Vedrana Ivezić, Moeyens Joachim

DiRAC members Joachim Moeyens and Zeljko Ivezić, aided by a DiRAC guest researcher Vedrana Ivezić, led a multi-institutional team of scientists who produced and analyzed simulated SPHEREx spectra of asteroids. 

SPHEREx is a 2-year NASA space mission scheduled for launch in less than 3 years. SPHEREx will deliver the first all-sky spectral survey at about 100 spectral channels in the infrared wavelength range 0.8-5.0 micron. The team estimated that SPHEREx dataset will be transformative: high-quality spectra will be obtained for close to 10,000 asteroids, representing an increase over our current sample size by more than an order of magnitude. 

With its additional LSST expertise, DiRAC will be well positioned to lead cutting-edge studies of asteroid taxonomy and photometric variability, and thus contribute to our understanding of the formation and evolution of our SolarSystem. 

ADS: Simulated SPHEREx spectra of asteroids and their implications for asteroid size and reflectance estimation

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

Published paper by Melissa Graham

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.

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.

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


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.