Patrick J. Vallely
Academic Background
My Ph.D. thesis focused broadly on constraining the origin and explosion characteristics of supernovae, although I worked on a wide range of topics during my graduate studies. I spent the majority of my time studying transients detected by the All-Sky Automated Survey for Supernovae (ASAS-SN), with a special emphasis on those simultaneously observed by NASA's TESS mission. The availiability of high-cadence data from TESS paired with the early ground-based detections from ASAS-SN made these events particularly valuable tools for constraining often-unobserved regimes in transient evolution. Our efforts paid off in a particularly big way with the discovery of ASASSN-19bt, one of the most well-observed tidal disruption events in history, an exciting find that I got to talk about in an interview with NPR.
In addition to working with data from the small telescopes of ASAS-SN and TESS, I also made extensive use of more conventional large ground-based telescopes like the twin 8.2m Large Binocular Telescope at Mount Graham International Observatory. All told, I spent nearly 70 full nights observing with LBT while at Ohio State, coordinating observations for the OSU-led research consortium and leading the program-specific planning and data reduction for nearly all transient-related observations from 2018 through 2022. In recognition of this work as well as my development of data reduction pipelines for TESS imagery, I was awarded the 2021 Allan K. Markowitz Award for excellence in observational astronomy.
I also have experience with numerical astrophysical modeling. During my undergraduate career at the University of Oklahoma I spent several years working with the Supernova Numerical Radiative Transfer Group, where I used the generalized stellar atmospheres code PHOENIX and its simpler cousin SYNOW to calculate model spectra for several flavors of explosive astrophysical transients. In this capacity I calculated model spectra for a number of interesting transients, ranging from the nearby Type Ia supernova SN 2014J to the predicted kilonova emission from a neutron star merger.
Beyond astronomy, I've dabbled in experimental condensed matter physics. At the University of Oklahoma I spent over a year working with the Photovoltaic Materials and Devices Group. My primary contribution was the assembly of a tabletop spectroscopy setup that, last I checked, is still being used to perform electroluminescence and photoluminescence measurements, but I also developed some simple theoretical models to help characterize the internal properties of quantum dot intermediate band solar cells, a primary focus for the research group.
Press Releases and Media Appearances
Lead Author Publications
- High-Cadence, Early-Time Observations of Core-Collapse Supernovae From the TESS Prime Mission
- ASASSN-18tb: A Most Unusual Type Ia Supernova Observed by TESS and SALT
- Signatures of Bimodality in Nebular Phase Type Ia Supernova Spectra
- The Highly Luminous Type Ibn Supernova ASASSN-14ms
- Supernova 2014J at M82 - II. Direct Analysis of a Middle-Class Type Ia Supernova
Selected Co-Author Publications
- Revealing AGNs through TESS variability
- Four Years of Type Ia Supernovae Observed by TESS: Early-time Light-curve Shapes and Constraints on Companion Interaction Models
- Chandra, HST/STIS, NICER, Swift, and TESS Detail the Flare Evolution of the Repeating Nuclear Transient ASASSN -14ko
- Examining the Properties of Low-luminosity Hosts of Type Ia Supernovae from ASAS-SN
- TESS shines light on the origin of the ambiguous nuclear transient ASASSN-18el
- Spectroscopy of TOI-1259B – An Unpolluted White Dwarf Companion to an Inflated Warm Saturn
- The 'Giraffe': Discovery of a Stripped Red Giant in an Interacting Binary With an 2 M⊙ Lower Giant
- The 2019 Outburst of the 2005 Classical Nova V1047 Cen: A Record Breaking Dwarf Nova Outburst or a New Phenomenon?
- Discovery of a Highly Eccentric, Chromospherically Active Binary: ASASSN-V J192114.84+624950.8
- Investigating the Nature of the Luminous Ambiguous Nuclear Transient ASASSN-17jz
- The Curious Case of ASASSN-20hx: A Slowly Evolving, UV- and X-Ray-Luminous, Ambiguous Nuclear Transient
- The Loudest Stellar Heartbeat: Characterizing the Most Extreme Amplitude Heartbeat Star System
- A Unicorn in Monoceros: The 3 M⊙ Dark Companion to the Bright, Nearby Red Giant V723 Mon is a Non-Interacting, Mass-Gap Black Hole Candidate
- SN2019yvq Does Not Conform to SN Ia Explosion Models
- ASASSN-14ko is a Periodic Nuclear Transient in ESO 253-G003
- The ASAS-SN Catalogue of Variable Stars - VIII. 'Dipper' Stars in the Lupus Star-Forming Region
- Discovery and Follow-Up of ASASSN-19dj: An X-Ray and UV Luminous TDE in an Extreme Post-Starburst Galaxy
- Direct Evidence for Shock-Powered Optical Emission in a Nova
- To TDE or Not To TDE: The Luminous Transient ASASSN-18jd with TDE-like and AGN-like Qualities
- The ASAS-SN Catalogue of Variable Stars VI: An All-Sky Sample of δ Scuti Stars
- The Shape of SN 1993J Re-Analysed
- Nebular Spectra of 111 Type Ia Supernovae Disfavour Single-Degenerate Progenitors
- The New EXor Outburst of ESO-Hα 99 Observed by Gaia ATLAS and TESS
- Discovery and Early Evolution of ASASSN-19bt, the First TDE Detected by TESS
- Early Time Light Curves of 18 Bright Type Ia Supernovae Observed with TESS
- The ASAS-SN Bright Supernova Catalog -- IV. 2017
- Seeing Double: ASASSN-18bt Exhibits a Two-component Rise in the Early-time K2 Light Curve
- Photometric and Spectroscopic Properties of Type Ia Supernova 2018oh with Early Excess Emission from the Kepler 2 Observations
- SN 2014J at M82 - I. A Middle-Class Type Ia Supernova by All Spectroscopic Metrics
- Investigation of InAs/GaAs1−xSbx Quantum Dots for Applications in Intermediate Band Solar Cells
Conference Posters and Presentations
- High-Cadence, Early-Time Observations of Core-Collapse Supernovae From the TESS Prime Mission
- Using TESS and SALT to Understand the Unusual Type Ia ASASSN-18tb
- TESS as a Transient Exploration Mission: Synergies With ASAS-SN and Other Ground-Based Supernovae Surveys
- ASAS-SN: Big Science with Small Telescopes
- Signatures of Bi-Modality in Nebular Phase Type Ia Supernova Spectra: Indications of White Dwarf Collision Progenitors
- ASASSN-14ms: An Unusually Luminous Type Ibn Supernova
- Modeling Kilonova Spectra Using PHOENIX