TEAM

Ryan Foley


Assistant Professor of Astronomy and Astrophysics

Lila Braff



Undergraduate Researcher


María José

Bustamante

Rosell



Postdoctoral Researcher

Srujan Dandu


Undergraduate Researcher

Kyle Davis


Graduate Student

Connor Dickinson


Undergraduate Researcher

Dominic Doud


Undergraduate Researcher

Aarna Garg


Undergraduate Researcher

Jack Kutcka


Predoctoral  Researcher

Zhisen Lai (Sam Lai)


Undergraduate Researcher

Phillip Macias


Postdoctoral Researcher

César Rojas-Bravo


Graduate Student

Kirsty Taggart


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

Kyle Davis


Graduate Student

I am a first-year graduate student working on Type Ia supernova spectroscopy with an emphasis on leveraging large spectroscopic samples to find out how we can improve cosmological distance measurements. In particular, I analyze spectroscopic diversity within uniform photometric spaces to consider what current models could be overlooking. I also observe and perform spectroscopic follow up with Lick, Keck, SOAR, and more for the Young Supernova Experiment collaboration. I attended UC Santa Cruz for two years before transferring to UC Los Angeles and receiving a B.S. in Astrophysics with a minor in Geophysics and Planetary Physics.



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.

Postdoctoral Researchers

María José Bustamante Rosell


Postdoctoral Researcher

I'm postdoctoral researcher working on the electromagnetic follow-up of gravitational wave events, work that I continue to focus on from my time as a PhD at the University of Texas at Austin, where I led a program doing spectroscopic follow-up of such events. During those years, I also worked in multiple other projects regarding black hole detection, from identifying supermassive black holes at the cores of galaxies by tracing the motion of the stars surrounding them, to contributing to the detection of binary black holes via their gravitational wave emission, both as a member of the LIGO and SXS collaborations as well as independently, devising new methods for detection based on the effect of gravitational waves on the propagation of gravitational waves. My current interests also spread towards leveraging new theoretical insights in galactic dynamics with the populations of different kinds of transient events, and what they can tell us about their host galaxies.

Phillip Macias


Postdoctoral 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.

PRedoctoral Researchers

Jack Kutcka


Predoctoral Researcher

I am a UCSC alumnus working with Kirsty Taggart on the Nickel Telescope supernovae observations and Peter McGill on the BLAST project. I am particularly interested in dark matter research.





Undergraduate Students

Lila Braff


Undergraduate Researcher

I am a third year Astrophysics student and have been a member of the Transient team for two years. Throughout my time on the team I have worked on coding documentation for Peter McGills’s project, Blast,  and I contributed to the programming of Ryan Foley's and Kirsty Taggart's project, Dark Hunters. Alongside these projects I also observe the Nickel telescope at Lick Observatory to gather supernova data for future analyzation by the team.







Srujan Dandu


Undergraduate Researcher

I am a fourth-year Astrophysics undergraduate student at UCSC. I am currently assisting Matt Siebert in updating information on Kaepora, an SQL database of Type Ia supernovae. I am also certified on the Nickel one-meter telescope at Lick Observatory, and regularly observe targets for the team using it.





Connor Dickinson


Undergraduate Researcher

I am currently an undergraduate astrophysics major at UCSC. My research as of now involves doing astrometry on supernovae targets with the help of Kirsty Taggart. I am also a certified and frequent operator for the Nickel telescope at the Lick Observatory. I have yet to settle down with a specific research interest, but as of now my primary interests revolve around supernovae events, exoplanetary atmospheres, and the telescopes themselves.



Dominic Doud


Undergraduate Researcher

I am a 2nd year Ventura Community College working on researching discovering, analyzing, and identifying trends in progenitor stars compared to their supernovae spectrum with Kirsty Taggart. Specifically, I utilize before and after data imagery from the Hubble Space Telescope and utilize photometry to identify potential progenitors' positions in both before and after images. From there, stellar models are plotted with the progenitor spectrum to find its properties. I have also shadowed observing Shane for classifications. I am transferring in Fall 2024 to UCSC, majoring in Astrophysics.





Aarna Garg


Undergraduate Researcher

I'm a second-year astrophysics major at UCSC. I currently observe Type 1a supernovae on the Nickel telescope at Lick Observatory. I also work alongside Majo Buro in the Dark Hunters project. As for my broader interests, I love cosmology and dark matter!



Zhisen Lai

(Sam Lai)


Undergraduate Researcher

I am an Astrophysics undergraduate student at UCSC. I am currently working on the automatic identification of bad data points with Professor Ryan in the Young Supernova Experiment. Also, I am certified on the one-meter Nickel telescope at Lick Observatory and perform observation regularly. I am exploring some topics, including black holes, dark energy, supernovas, and gravitational wave. So, I could settle down my research topics in the future.


Alumni

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 a PhD student at Johns Hopkins University, currently working on light echoes with Armin Rest at Space Telescope Science Institute. If you want to contact me, my email is roangulo@ucsc.edu.


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.

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.

Payton Crawford


Undergraduate Researcher

 I am a fourth year Astrophysics undergraduate student at UCSC. I am working with David Jones studying Type 1a Supernovae, and how to use them to measure the rate of expansion of the Universe. I enjoy observing transient events and analyzing their data to learn more about them. I am particularly interested in  Type 1a progenitors and dark energy.



Georgios Dimitriadis


Posdoctoral 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.

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 UC Berkeley in 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.




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.

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.



David Jones


Assistant Astronomer,

NOIRLab

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.

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.

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.

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. 

Matthew Siebert


NSF Graduate Research Fellow

I work 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/).

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.


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.

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.