I am currently at the Department of Astronomy at University of Arizona as an Assistant Professor. Previously I was a RPF Distinguished Postdoctoral Fellow at Los Alamos National Laboratory in the Computational Physics and Methods (CCS-2) and Eulerian Codes (XCP-2) Divisions. I am broadly interested in computational and nuclear astrophysics of massive stars, their explosions and the multi-messenger signals they produce.

Peter studies the optical counterparts of Gamma Ray Bursts. He is a co-investigator on the Super-LOTIS (Livermore Optical Transient Imaging System), a robotic telescope that searches for these objects. He also works in the emerging field of positron astrophysics.

I am a physicist with interest in astronomy because of the wide range of phenomena and processes occurring astrophysical context. I focus mostly on stellar astrophysics, and in particular massive stars, binary evolution, and stellar explosions. My research interest include stellar kinematics (runaway, "walkaway", and hyper-velocity stars), core-collapse and (pulsational) pair-instability supernovae, X-ray binaries, time-domain and gravitational-wave astronomy. I mainly use analytical and numerical simulations to understand massive star evolution, their explosions, and how they interact in binary systems. I use both detailed stellar structure and evolution models (e.g., with MESA, and rapid population synthesis (e.g., with binary c or COSMIC). I am learning to run hydrodynamical simulations (with ATHENA++).

Postdocs

• Aldana Grichener

Dr. David Sand is an observational astronomer with a variety of interests. He spends a lot of his time searching for and understanding the smallest galaxies in the Universe, as they are extremely dark matter dominated and are signposts for structure formation. Dr. Sand is also broadly interested in time domain astronomy, and in particular understanding the progenitors and explosion mechanisms of supernovae. Dr. Sand does some instrument development to further his team's scientific goals.

Postdocs

• Manisha Shrestha
• Azalee Boestrom
• Bhagya Subrayan

Students

• Jeniveve Pearson

Dr. Nathan Smith is interested in understanding the evolution and fate of massive stars, and their influence on the surrounding interstellar medium. His primary focus is on the violent explosions and eruptions that occur as a massive star approaches its death, especially those of the most massive and luminous stars known. Although these stars drive the energetics of the interstellar medium and are extremely bright and easy to observe, the way they reach their demise and finally explode is still very poorly understood. Nathan specializes in multiwavelength spectroscopy and high-resolution imaging of supernovae and other transients in order to study explosions observed in real time, and he studies spatially resolved circumstellar material in order to constrain the physical properties of mass-loss episodes that have occurred in the past.

Another main area of interest is the evolution of massive star-forming regions, where energy input from the radiation, winds, and explosions of massive stars can influence star and planet formation in the surrounding cloud. Nathan performs detailed mutiwavelength studies of nearby stellar nurseries, working toward a complete picture of the complex processes that dominate the massive star-forming environment, trying to understand the interplay between star death and birth. This impacts our own origins, since the Solar system is thought to have formed in such a region, probably exposedto nearby supernovae.

Nathan conducts observations using the Hubble Space Telescope and other NASA missions, plus numerous ground-based optical/infrared telescopes. Although primarily an observer, he incorporates theoretical tools in his work, and has a broad interest in Galactic astronomy including stellar evolution, mass loss, circumstellar material, shock physics, HII regions, disks, jets, planetary nebulae, dust formation, and nebular spectroscopy. Nathan earned undergraduate degrees in music and astronomy, plus a master's degree and a Ph.D. in Astrophysics.

Students

• Brian Hsu

Hi, I'm an Assistant Astronomer at NSF's NOIRLab in Tucson, AZ, and was born and raised in Honolulu, Hawaii. My research focuses on massive evolved stars, infrared transients, dust production/destruction, obscured high-mass x-ray binaries, and star formation.

I'm an infrared astronomer, which is a tricky wavelength to observe since almost everything around us (on Earth) is emitting infrared photons like crazy, and water vapor in our atmosphere absorbs infrared photons from the astronomical targets we are interested in. However, we can overcome these challenges with observatories up on the highest mountains on Earth, observatories that fly into the stratosphere, and observatories up in space. This is why it's great having awesome facilities like Keck, Subaru, Gemini, SOFIA, and JWST.

The science that we can learn from these infrared observatories is absolutely worth it. In the infrared, we can peer into the densest clouds to reveal the birth of new stars, probe the material ejected from massive stars as they near the end of their lives, and even trace the outcome of merging neutron stars that also produce gravitational waves signatures.

I'm an astronomer at the University of Arizona and the current Director of the MMT Observatory. I earned a Bachelor’s degree in Physics from the University at Buffalo in 1994 and a PhD from Clemson University in 2000.

My research focuses on the evolution of cool supergiant stars, with the aim of constraining the progenitor-supernova-remnant connection. I do this using both observations and stellar evolution models of red supergiants, yellow supergiants, and supernovae remnants. I am also interested in using massive stellar populations (such as Westerlund 1) as a tool for understanding single and binary stellar evolution. Ultimately, I hope to determine which stars explode, what those explosions look like, and which fail to explode entirely.

I am an LSSTC Catalyst Fellow at University of Arizona where I am working on connecting massive star supernovae to their progenitor. In addition to understanding exploding stars, I am a strong proponent of open source development, tools, and open science. I believe science is better when we help each other succeed and passionately promote education and equity.​

My name is Aldana Grichener and I am a theoretical astrophysicist interested in the connection between massive binary stars and high energy astrophysical phenomena. I am currently a Steward Observatory Theory Fellow/IAU-Gruber Fellow/CHE Fellow in the University of Arizona and Steward Observatory. I have been working on a broad range of topics, including but not restricted to heavy elements, peculiar transients, feedback mechanisms in stellar outflows, common envelope evolution, high energy neutrinos and morphologies of supernova remnants.

Manisha joined Steward Observatory in the fall of 2022 to work with Prof. David Sand. Her research focuses on studies of transients such as gamma-ray bursts, young supernovae, and kilonovae. During her previous postdoctoral position at Astrophysics Research Institute in Liverpool, she used optical observations of gamma-ray bursts to study their magnetic field properties. In addition, she has been working on computational simulations of kilonovae emissions to predict their photometric and polarimetric behavior. She is interested in using these kilonova models to understand better the physics of the electromagnetic counterparts of gravitational wave sources. She received her PhD from the University of Denver in 2018.

I’m currently a Postdoctoral Research Associate at Steward Observatory at the University of Arizona , working with Prof. Dave Sand to study young, nearby supernovae and investigate the formation of dust in core-collapse supernova (CCSNe) ejecta . Using the powerful capabilities of the James Webb Space Telescope (JWST) , my research is focused on understanding these energetic explosions and their impact on dust production in the universe.​

I am an Astrophysics Ph.D. student at the University of Arizona. My research interests broadly fall within the field of time-domain astronomy, with a focus on extragalactic transients and stellar variability. I am currently working with Dr. Kate Alexander on studying the radio counterparts of Tidal Disruption Events (TDEs). I am also a former member of the All-Sky Automated Survey for SuperNovae (ASAS-SN) team and a current collaborator and researcher for Citizen ASAS-SN. I graduated from The Ohio State University in 2021, with a Bachelor's of Science in Astronomy and Physics.

I study the high-redshift transient universe with JWST as a member of the JWST Advanced Deep Extragalactic Survey (JADES) team. My work involves surveying deep near/mid-infrared images for transient events and classifying these transient events, which has uncovered many of the most distant supernovae discovered to date. I am interested in constraining core-collapse supernova rates in the early universe and hope to uncover exotic transient events such as superluminous supernovae. My research advisor is Dr. Eiichi Egami, and I have been working with him since I arrived at University of Arizona in 2021. Before I started working on transient science, I studied galaxies with the VLA, and I still continue to enjoy contributing to JWST galaxy papers as a JADES team member.

In spring 2023, I graduated from Siena College with a B.S. Degree. In undergraduate, I double majored in Physics and Applied Data Science and obtained minors in Astronomy and Mathematics. During these four years, I also discovered my strong interests in astronomy, big data, data science, and programming. Throughout undergraduate, I explored a wide variety of research interests including working with the Dark Energy Spectroscopic Instrument, Berkeley Search for Extraterrestrial Intelligence, and The University of Hawaii Institute for Astronomy.

In fall 2023, I started applying these interests as an Astronomy graduate student at the University of Arizona Department of Astronomy (Steward Observatory). I am motivated to study astronomy by the possibilities to unravel deep mysteries of the universe. One area I am especially interested in is understanding black holes. As a result, I plan to study transients like tidal disruption events which can provide important insight into the area surrounding these mysterious objects.

I am a first-year Ph.D. student in Astronomy and Astrophysics at Steward Observatory, University of Arizona. I graduated with a B.A. in Astrophysics and Physics from Harvard University in 2023, where I worked with the Berger Cosmic Transients Lab on the optical study of Type I superluminous supernovae and UV analysis of their host galaxies, as well as applying machine learning techniques in preparation for the Vera C. Rubin Observatory Legacy Survey of Space and Time.

Currently, I am working with Prof. Nathan Smith and Dr. Grant Williams on studying the simultaneous temporal evolution of spectropolarimetric, spectroscopic, and photometric properties of Type IIn supernovae.

I am originally from Queens, New York, but spent most of my childhood in Taiwan. In my spare time, I like to play volleyball, do yoga, and recently I’ve been trying to learn how to crochet.

Vikram is a theoretical and computational astrophysicist whose research focuses on the multi-messenger nature of compact objects such as binary black holes, neutron stars, supernovae, and other high-energy transients. He uses numerical relativity and magnetohydrodynamic simulations, such as Einstein Toolkit, IllinoisGRMHD, and Athena++, to study these systems in a variety of contexts. His current work focuses on the late-time evolution of accreting supermassive black hole binaries in the LISA band. Future work will hopefully expand the current numerical framework to study core-collapse supernova and other high-energy transients.

Jeniveve focuses on studying young supernovae in the nearby universe to understand their progenitors and explosion mechanisms. She is also interested in late-stage red supergiants, particularly on the higher mass end (18-30 M$_\odot$), and predicting the final moments of their lives. Jeniveve has been a PhD student working under David Sand since 2020, when she came to University of Arizona after graduating with a B.S. from The Ohio State University with a double major in Physics and Astrophysics and a minor in Studio Art.