05/05/2021 - A curiously yellow star has caused astrophysicists to reevaluate the possible pathways that can lead to the explosion of a massive star as a supernova. An international team including UC Santa Cruz astrophysicists used observations from NASA’s Hubble Space Telescope taken two-and-a-half years before the star exploded to identify and study the massive star that became supernova SN 2019yvr.

03/16/2021 - In June 2017, César Rojas-Bravo left Costa Rica a couple of months early to ease his transition into graduate school in the United States. Instead, he was thrown into a whirlwind discovery that most scientists only ever dream of. Read the profile of César and his experience discovering the first optical counterpart to a gravitational wave source in the newest LIGO magazine.

This image from a computer simulation shows the rapid formation of an accretion disk during the disruption of a star by a supermassive black hole. (Image credit: Jamie Law-Smith and Enrico Ramirez-Ruiz)

08/26/2020 - New tidal disruption event observations led by astronomers at UC Santa Cruz now provide clear evidence that debris from the star forms a rotating disk, called an accretion disk, around the black hole. Theorists have been debating whether an accretion disk can form efficiently during a tidal disruption event, and the new findings should help resolve that question, said first author Tiara Hung, a postdoctoral researcher on the UC Santa Cruz Transients Team.

08/05/2020 - An international team led by UC Santa Cruz Transients' Wynn Jacobson-Galán has potentially uncovered the nature of “calcium-rich supernovae,” rare stellar explosions that astrophysicists have struggled to find and study. For the first time ever, the researchers examined these rare, mysterious events with x-ray imaging, which provided an unprecedented glimpse into the star during the last month of its life and ultimate explosion.

03/27/19 - A new UC Santa Cruz alumni travel program that will link travelers with some of the campus’s best and brightest professors for a deep dive into a trove of fascinating places. Called Inspired Expeditions, one of those trips features Assistant Professor of Astronomy and Astrophysics Ryan Foley, who will take visitors to various observatory sites in Chile before they witness a total solar eclipse in December 2020

02/05/19 - UC Santa Cruz undergraduates Wynn Jacobson-Galán, Catherine Manea and Zafar Rustamkulov were each winners of the Chambliss Astronomy Achievement Student Awards at the 233rd meeting of the American Astronomical Society (AAS) in Seattle. Each presented research in a poster session at the meeting and won a medal in recognition of their work. Jacobson-Galán, a member of the UC Santa Cruz Transients Team led by astrophysicist Ryan Foley, won for a presentation entitled "Evidence of helium emission provides progenitor constraints in Type Iax supernovae."

01/08/2018- Both Science and Physics World noted the significance of the findings in which UC Santa Cruz astronomers played a key role. The blast confirmed several key astrophysical models, revealed a birthplace of many heavy elements, and tested the general theory of relativity as never before. That first observation of a neutron-star merger, and the scientific bounty it revealed, is Science's 2017 Breakthrough of the Year."

03/13/18 - The 2018 NEXTies, a local awards show celebrating the best and brightest in the Santa Cruz community honored astronomer Ryan Foley in the "Wildcard" category for his leadership in a spectacular event that galvanized the international astronomy community.

11/13/2018 - UCSC astronomers examined surprising images of a Type Ia supernova, from the moment of explosion through the rise and fall of the light curve, which revealed unexpected early rise in brightness and provided new insight on the expansion of the universe. "My jaw just dropped," said Georgios Dimitriadis, a UC Santa Cruz Transients postdoctoral researcher who was one of the first to examine the data and led the study.

11/15/2018 - The UC Santa Cruz Transients Team uncovered an ultra-rare glimpse leading up to a supernova known as type Ic, which is thought to detonate after its massive progenitor star has shed or been stripped of its outer layers of hydrogen and helium. Postdoctoral Fellow Charlie Kilpatrick poured through the archive of NASA's Hubble Space Telescope images to uncover the putative progenitor in pre-explosion photos taken in 2006.

10/18/2017 - As one of the first astronomy teams in the world to observe the explosion of two colliding neutron stars, the UC Santa Cruz Transient Astrophysicists have revealed new details about the a catastrophic merger so violent that it distorts space and time to create gravitational waves. Astronomer Ryan Foley says this is probably the biggest discovery he’ll make in his lifetime.

The merger of two neutron stars generated a bright kilonova observed by UC Santa Cruz astronomers, as depicted in this artist's illustration. (Credit: NSF/LIGO/Sonoma State University/A. Simonnet)

10/16/2017 - The UC Santa Cruz Transients Team was the first to observe light from a gravitational wave source, which turned out to be a brilliant explosion caused by the merger of two neutron stars. This momentous discovery offered proof that astronomers could look at the universe two different ways like being able to see and hear something at the same time, kicking off a new era of gravitational wave astrophysics.

The yellow arrow marks the superluminous supernova DES15E2mlf in this false-color image of the surrounding field. This image was observed with the Dark Energy Camera (DECam) gri-band filters mounted on the Blanco 4-meter telescope on December 28, 2015, around the time when the supernova reached its peak luminosity. (Observers: D. Gerdes and S. Jouvel)

07/21/2017 - At a distance of 10 billion light years, a supernova detected by the Dark Energy Survey team is one of the most distant ever discovered. The investigation was led by UC Santa Cruz astronomers Yen-Chen Pan and Ryan Foley as part of an international team of collaborators using the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory in Chile. Follow-up observations to measure the distance and obtain detailed spectra of the supernova were conducted with the Gemini Multi-Object Spectrograph.

04/17/2017 - UC Observatories, Lick Observatory, and the Department of Astronomy and Astrophysics offer a Star Party, replete with jazz, informative talks from foremost experts on astronomy, constellation identification, and telescopes for viewing celestial objects. Prof. Ryan Foley will give a history of Lick Observatory before the viewing.

New faculty in the Department of Astronomy and Astrophysics. Top row: professor Ruth Murray-Clay, assistant professor Ryan Foley, and assistant professor Alexie Leauthaud. Bottom row: adjunct professor Kevin Bundy, associate professor Brant Robertson, and assistant professor Andrew Skemer.

11/28/2016 - Six new faculty members have joined the Department of Astronomy and Astrophysics, bringing with them a wide range of expertise in some of the most exciting areas of astronomy and cosmology. Among them is assistant professor Ryan Foley, an astrophysicist who studies exploding stars (supernovae) and other transient celestial phenomena, and uses supernova observations to study dark energy and cosmology.

Ryan Foley (photo by Emily Teague)

10/14/2016 - The David and Lucile Packard Foundation awarded a Packard Fellowship for Science and Engineering to Ryan Foley, assistant professor of astronomy and astrophysics at UC Santa Cruz. The Packard Fellowship, one of the nation's most prestigious honors for scientists, gives Foley a grant to support his research on the mysterious "dark energy" that is causing the expansion of the universe to speed up.


Observations of tidal disruption event reveal rapid disk formation


Einstein, Hubble and Dark Energy

Prof. Foley and the next breakthrough on the UCO Living Room Lecture

Merging Neutron Stars

Historic observation kicks off new era in astronomy

INSide Story Behind A Huge Discovery

Postdoctoral researcher Dave Coulter takes us behind the scenes

Shining Light On Gravity

Prof. Ryan Foley shines a light on gravity

Infared Survey and Cosmic Mysteries

The Wide Field Infrared Survey Telescope (WFIRST) gets green light from NASA

Observing Supermassive Blackholes

Ejecting dying stars from host

Supernova Astronomy Evolving

Prof. Ryan Foley speaks at Carnegie Sciences Observatories

Gravitational Wave ELectromagnetic Counterpart

Prof. Ryan Foley speaks at Texas A&M on merger of a binary neutron star system

Multiple Progenitors For SN Type Ia

Prof. Ryan Foley's 2016 talk at the Sackler Confrence in Cambridge

Astronomy On Tap

Select team members speak on topical issues in Astronomy

Universe In Motion

UCSC Astronomers speak about Astronomy on Tap series

Brown Dwarfs: too Small or Too Big

Postdoctoral Researcher Kaew Tinyanont presents at CalTech

Social Media


Facebook Groups