TEAM

Ryan Foley


Assistant Professor of Astronomy and Astrophysics

Rodrigo Angulo


Pre-doctoral Researcher

David Coulter


NSF Graduate Research Fellow

Georgios Dimitriadis


Posdoctoraral Researcher

Tiara Hung


Postdoctoral Researcher

Jessica Johnson


Undergraduate Researcher

David Jones


NASA Einstein Fellow

Phillip Macias


Posdoctoral Researcher

César Rojas-Bravo


Graduate Student

Matthew Siebert


NSF Graduate Research Fellow

Carli Smith


Pre-doctoral Researcher

Kirsty Taggart


Postdoctoral Researcher

Kaew Tinyanont


Postdoctoral Researcher











Faculty

Ryan Foley


Assistant Professor of Astronomy and Astrophysics



Prof. Foley studies exploding stars, often with a telescope from the top of a mountain. He is interested in characterizing the many ways a star can die. He received his PhD from UC Berkeley in 2008, was a Clay Fellow at the Harvard-Smithsonian Center for Astrophysics, and is now a member of the UC Santa Cruz faculty. He is a Sloan fellow, Packard fellow, and Kavli fellow. He was awarded a 2018 NEXTies award in the “Wildcard” category. His team’s discovery of the first light from a gravitational wave source was named the 2017 Science Breakthrough of the Year. He lives close to the beach and tries to see the ocean every day.

Graduate Students

David Coulter


NSF Graduate Research Fellow



I am a fifth-year graduate student primarily working on finding and characterizing electromagnetic (EM) counterparts to gravitational wave (GW) sources. These GW sources are generated by the most extreme events in the universe: the mergers between two black holes, two neutron stars, or a black hole-neutron star system. In August of 2017 our team discovered the first optical counterpart to such a system -- the merger of two neutron stars -- and in the process helped confirm the link between these events and short gamma ray bursts, as well as their role in synthesizing the heaviest elements. Coming from a software development background I write a variety of software for our team, in particular an observational planning and analysis tool to study these EM counterparts (Teglon: https://github.com/davecoulter/teglon), have architected and developed the Young Supernova Experiment's transient management framework (a MySQL-based web application YSE-PZ: https://github.com/davecoulter/YSE_PZ), and have worked on a variety of other science and infrastructure projects with topics ranging as wide as tidal disruption events and cosmology, to data-reduction and telescope scheduling services. I am an NSF Graduate Research fellow and received my B.S. in Physics from Portland State University in 2015.

César Rojas-Bravo


Graduate Student

I’m a fourth-year Ph.D. student working on Type Ia Supernova Cosmology as part of the Swope Supernova Survey, using the Swope 1-m telescope at Las Campanas Observatory, Chile. I’m also part of the Young Supernova Experiment, Foundation Supernova Survey, 1-Meter 2-Hemisphere Collaboration and Vera Rubin Dark Energy Science Collaboration. I obtained a B.S. in Physics and a B.A. in Classical Philology at Universidad de Costa Rica. You can find out more about me here.

Matthew Siebert


NSF Graduate Research Fellow

I am a fifth-year graduate student working on optical spectroscopy of Type Ia supernovae and their host galaxies. I am particularly interested in probing the physics of these phenomena in order to improve our cosmological distance measurements. I built the SQL database (kaepora) to facilitate this research. I received my undergraduate degree in Engineering Physics from Cornell University. You can find more about my research and kaepora here (https://msiebert1.github.io/).

Postdoctoral Researchers

Georgios Dimitriadis


Posdoctoraral Researcher



I am a postdoctoral researcher focusing on studies of thermonuclear explosions. I use photometric and spectroscopic observations to study the progenitor problem and the explosion physics of thermonuclear transients. I received my undergraduate degree in physics from the Aristotle University of Thessaloniki and my masters degree from the University of Amsterdam. I obtained my PhD from the University of Southampton, where my thesis was focused on observational constraints on the progenitor system of type Ia supernovae.

Tiara Hung


Postdoctoral Researcher

I am a postdoctoral researcher working on tidal disruption events (TDEs). I developed customized programs to find these rare transients from optical sky surveys and study them with multi-wavelength follow up observations. I am interested in a broad set of astrophysical insights that TDEs may offer, such as black hole demographics and accretion disk formation, and super-Eddington accretion. I received my master and PhD in astronomy from the University of Maryland, where my thesis focused on black hole related transient phenomena - AGN variability and TDEs.

David Jones


NASA Einstein Fellow

I’m working to understand the physics of the 70% of our universe comprised of dark energy, the mysterious cause of cosmic acceleration, and to measure the expansion rate of the nearby universe (the Hubble constant) using Type Ia supernovae as cosmological tools. I’m currently the Project Scientist of the Young Supernova Experiment, a new time-domain survey to understand stellar explosions and enhance the sample of nearby, well-observed supernovae. I did my PhD work at Johns Hopkins University and I’m currently an Einstein postdoctoral fellow at UCSC. Please reach out if you’re interested in working with me on any of these topics.

Phillip Macias


Posdoctoral Researcher

I’m a postdoctoral researcher working on simulating observations of type Ia supernovae with the Nancy Grace Roman Space Telescope to maximize its cosmological use. I received my undergraduate degree in physics from UC Santa Barbara and my PhD from UC Santa Cruz, where my thesis focused on constraining the progenitor systems of r-process nucleosynthesis. You can find out more about me here.

Kirsty Taggart


Postdoctoral Researcher

I am a postdoctoral researcher interested in using large, statistical samples of supernovae from wide-field surveys such as YSE to characterise the huge diversity in the observational and physical explosion properties of supernovae and to help uncover the manner in which the biggest stars die.

I obtained my Master’s degree at the University of Sheffield, spending a year at the University of Western Australia. Following that, I completed my PhD at Liverpool John Moores University, where my thesis focused on the progenitors and environments of extreme (superluminous) supernovae.

Kaew Tinyanont


Postdoctoral Researcher

I am interested in the life and death of massive stars. They live a brief, tumultuous, but consequential life, resulting in a powerful core-collapse supernova. I use observations of these supernovae to probe their circumstellar material ejected from the progenitor stars in different phases of their life. I am also interested in spectropolarimetry of supernovae, which can uniquely provide geometric information of the unresolved supernova ejecta. The ejecta geometry is shaped by the explosion mechanism of the supernova itself and also the environment in which it explodes. I obtained my undergraduate degree in physics from Harvey Mudd College. I obtained my masters and doctoral degrees in astronomy from California Institute of Technology.

PRe-doctoral Researchers

Rodrigo Angulo


Pre-doctoral Researcher

I am a recent graduate from UC Santa Cruz with a Bachelor of Science degree in Astrophysics and a Bachelor of Arts degree in Mathematics with concentration in Pure Mathematics. I am currently working as a junior specialist at UCSC on a project regarding type Ia supernovae. I am investigating the presence of carbon in supernovae and I want to learn more about astrophysics in general, so I can broaden my experience and prepare myself for graduate school and pursuing a PhD. If you want to contact me, my email is roangulo@ucsc.edu.


John Lopez


Post-undergraduate Researcher

I am a recent graduate from UC Santa Cruz, with a Bachelor of Science degree in Astrophysics. My focus is on Type Ia supernovae. Currently, I am working with Dr. Charlie Kilpatrick on investigating the Nickel-56 mass content of a sample of nearly 90 Type Ia supernovae through analyzing late-time data sets from the Hubble Space Telescope (HST). The goal of this project is to correlate the mass of Nickel-56 with other observables such as ejecta velocity, peak luminosity, and local environment that might give us clues as to the single- or double-degenerate origin of these explosions. I am also a certified observer with the Nickel Telescope on Mount Hamilton. Please contact me at jostlope@ucsc.edu with any questions.

Carli Smith


Pre-doctoral Researcher

I am a recent graduate from UC Santa Cruz, with a Bachelor of Science degree in Astrophysics. I work as a junior specialist, currently focusing on core-collapse supernovae. I study the relationship between Type II supernovae and their progenitor counterparts in an effort to understand the red supergiant problem. In the future I also hope to work on the the Young Supernova Experiment (YSE) collaboration. I am also certified with the Nickel telescope on Mount Hamilton and perform observations regularly for the team.


Undergraduate Students

Jessica Johnson


Undergraduate Researcher

I am an Astrophysics undergraduate student at UCSC studying a tidal disruption event from the Dark Energy Survey with Tiara Hung and Ryan Foley. I started this research through the Lamat intern program at UCSC. I really enjoy observing transient events on the Shane and Nickel telescopes at Lick Observatory with this team. I also research star forming regions in Ultra-Diffuse Galaxies with Aaron Romanowksy. I am the most interested in observational astronomy, spectroscopy, and extreme phenomena.



Alumni

Jonathan Brown

Data Scientist

Jon Brown joined the UCSC Transients Astrophysics group in 2018. He primarilyworked on data infrastructure and tooling, and also the opportunity to do plenty of observing, including observing runs in both Chile and Hawaii. In 2019, Jon made the difficult decision to move into industry as an Insight Data Science Fellow. Today he is a Data Scientist at HeadSpin working on a variety of projects relating to application performance at the edge.

Michael Foley

NSF Graduate Research Fellow

Michael is an NSF Graduate Research Fellow at Harvard University, where he is a third-year graduate student working on simulations and observations of stellar feedback and turbulence. He is particularly interested in understanding how shocks interact with turbulence and influence star formation. Michael was an undergraduate at Notre Dame who worked with the UC Santa Cruz team from 2016 to 2018 on understanding the light curves of Type Ia supernovae. He was also a summer undergraduate researcher in 2017.


Wynn Jacobson-Galán

Graduate Research Fellow

Wynn is currently an NSF Graduate Research Fellow at Northwestern University working in Prof. Raffaella Margutti’s research group. His primary research focuses on combining multi-wavelength (x-ray to radio) observations of core-collapse supernovae to create a complete picture of stellar instability and mass-loss in massive stars before explosion. Wynn was an undergraduate researcher and a junior specialist in Prof. Foley’s group from 2016-2019 where he worked on the progenitor systems of peculiar thermonuclear transients.




Charlie Kilpatrick

Postdoctoral Scholar

Charlie is currently a postdoctoral scholar at Northwestern University. At Northwestern and Santa Cruz, Charlie studied optical, infrared, and radio astronomy with a research focus on the pathways by which massive stars evolve and explode. He uses pre-explosion images and the supernova remnants left behind by massive stars to study the turbulent final years of stellar evolution. He is also closely involved in transient surveys and gravitational wave follow up efforts. He was the first person to see and identify the optical counterpart to the LIGO/Virgo binary neutron star merger GW170817.

Yen-Chen Pan

Assistant Professor

Yen-Chen is an assistant professor at National Central University in Taiwan. His research interest focuses on spectroscopic and host-galaxy studies of Type Ia supernovae. He is also interested in the mysterious Superluminous supernovae and their potential usage in cosmology. Yen-Chen worked with Ryan Foley as a postdoctoral researcher from 2014-2018.

Erika Strasburger

Graduate Student

Erika is currently a graduate student at UC Berkeley working under Prof. Filippenko. She is a Berkeley Chancellor's Fellow and an NSF Graduate Research Fellow. Her research interest focuses on investigating the explosion physics and asymmetry of thermonuclear supernovae through the use of light echoes. She worked with Prof. Foley's team as an undergraduate researcher from 2018-2020 where she worked on a late-time spectroscopic study of Type Ia supernovae.