Publications (26)
An isolated mass gap black hole or neutron star detected with astrometric microlensing
Casey Y. Lam, Jessica R. Lu, Andrzej Udalski +42
We present the analysis of five black hole candidates identified from gravitational microlensing surveys. Hubble Space Telescope astrometric data and densely sampled lightcurves fr…
The WINTER Observatory: A One-Degree InGaAs Survey Camera to study the Transient Infrared Sky
Danielle Frostig, Nathan Lourie, Viraj Karambelkar +20
The Wide-field Infrared Transient Explorer (WINTER) is a near-infrared time-domain survey instrument operating on a dedicated 1-meter robotic telescope at Palomar Observatory. The…
Operational Research: Methods and Applications
Fotios Petropoulos, Gilbert Laporte, Emel Aktas +79
Throughout its history, Operational Research has evolved to include a variety of methods, models and algorithms that have been applied to a diverse and wide range of contexts. This…
A Link Between White Dwarf Pulsars and Polars: Multiwavelength Observations of the 9.36-Minute Period Variable Gaia22ayj
Antonio C. Rodriguez, Kareem El-Badry, Pasi Hakala +30
White dwarfs (WDs) are the most abundant compact objects, and recent surveys have suggested that over a third of WDs in accreting binaries host a strong (B 1 MG) magnetic…
Multi-color characterization of optically invisible FU Orionis-type outbursts: Demonstration and prospects for the WINTER survey
Danielle Frostig, Kishalay De, Lynne A. Hillenbrand +8
Episodic mass accretion is the dominant mechanism for mass assembly in the proto-stellar phase. Although prior optical time-domain searches have allowed detailed studies of individ…
Investigating the Electron Capture Supernova Candidate AT 2019abn with JWST Spectroscopy
Sam Rose, Ryan M. Lau, Jacob E. Jencson +5
The James Webb Space Telescope (JWST) has opened up a new window to study highly reddened explosive transients. We present results from late-time (1421 days post-explosion) JWST fo…
The Impact of Initial-Final Mass Relations on Black Hole Microlensing
Sam Rose, Casey Y. Lam, Jessica R. Lu +5
Uncertainty in the initial-final mass relation (IFMR) has long been a problem in understanding the final stages of massive star evolution. One of the major challenges of constraini…
An infrared echo from a circumstellar disk in the hydrogen- and helium-poor SN 2024aecx
Samaporn Tinyanont, Kittipong Wangnok, Jennifer E. Andrews +34
We present near-infrared (NIR) spectroscopy of the hydrogen- and helium-poor (Type Ic) supernova (SN) 2024aecx, which displays a strong NIR excess emerging 32 days post peak. SN 20…
Twin peaks: SN 2021uvy and SN 2022hgk in the landscape of double-peaked stripped envelope supernovae
Yashvi Sharma, Jesper Sollerman, William Meynardie +25
In recent years, a class of stripped-envelope supernovae (SESNe) showing two distinct light-curve peaks has emerged, where the first peak cannot be attributed to shock cooling emis…
An optical to infrared study of type II SN2024ggi at nebular times
Luc Dessart, Rubina Kotak, Wynn Jacobson-Galan +5
We present 0.3-21mic observations at ~275d and ~400d for Type II supernova (SN) 2024ggi, combining ground-based optical and near-infrared data from the Keck I/II telescopes and spa…
Preferential Occurrence of Fast Radio Bursts in Massive Star-Forming Galaxies
Kritti Sharma, Vikram Ravi, Liam Connor +24
Fast Radio Bursts (FRBs) are millisecond-duration events detected from beyond the Milky Way. FRB emission characteristics favor highly magnetized neutron stars, or magnetars, as th…
Revealing a main-sequence star that consumed a planet with JWST
Ryan M. Lau, Jacob E. Jencson, Colette Salyk +8
The subluminous red nova (SLRN) ZTF SLRN-2020 is the most compelling direct detection of a planet being consumed by its host star, a scenario known as a planetary engulfment event.…
Assessing the Impact of Binary Systems on Microlensing Using SPISEA and PopSyCLE Population Simulations
Natasha S. Abrams, Jessica R. Lu, Casey Y. Lam +3
Gravitational microlensing provides a unique opportunity to probe the mass distribution of stars, black holes, and other objects in the Milky Way. Population simulations are necess…
Low-Luminosity Type IIP Supernovae from the Zwicky Transient Facility Census of the Local Universe. I: Luminosity Function, Volumetric Rate
Kaustav K. Das, Mansi M. Kasliwal, Christoffer Fremling +51
We present the luminosity function and volumetric rate of a sample of Type IIP supernovae (SNe) from the Zwicky Transient Facility Census of the Local Universe survey (CLU). This i…
Multiwavelength Analysis of Six Luminous Fast Blue Optical Transients
Cassie Sevilla, Anna Y. Q. Ho, Nayana A. J. +43
We present multiwavelength observations and analysis of six luminous fast blue optical transients (LFBOTs) discovered in Zwicky Transient Facility (ZTF) survey data. We identified…
EP250827b/SN 2025wkm: An X-ray Flash-Supernova Powered by a Central Engine and Circumstellar Interaction
Gokul P. Srinivasaragavan, Dongyue Li, Xander J. Hall +100
We present the discovery of EP250827b/SN 2025wkm, an X-ray Flash (XRF) discovered by the Einstein Probe (EP), accompanied by a broad-line Type Ic supernova (SN Ic-BL) at $z = 0.119…
A Mass Transferring Brown Dwarf Binary on a 57 Minute Orbit
Samuel Whitebook, Antonio C. Rodriguez, Kevin Burdge +9
Mass transfer in stellar binaries has been well studied in most stellar mass ranges, with the notable exception of ultracool stars and substellar brown dwarfs. We report the discov…
Dramatic rebrightening of the type-changing stripped-envelope supernova SN 2023aew
Yashvi Sharma, Jesper Sollerman, Shrinivas R. Kulkarni +32
Multi-peaked supernovae with precursors, dramatic light-curve rebrightenings, and spectral transformation are rare, but are being discovered in increasing numbers by modern night-s…
Low-Luminosity Type IIP Supernovae from the Zwicky Transient Facility Census of the Local Universe. III: Hunting for electron-capture supernovae using nebular spectroscopy
Kaustav K. Das, Anders Jerkstrand, Mansi M. Kasliwal +18
Electron-capture supernovae (ECSNe) may arise from ONeMg-core collapse in super-asymptotic giant branch (sAGB) stars near the low-mass core-collapse limit (--\,\Msu…
AppleCiDEr II: SpectraNet -- A Deep Learning Network for Spectroscopic Data
Maojie Xu, Argyro Sasli, Alexandra Junell +21
Time-domain surveys such as the Zwicky Transient Facility (ZTF) have opened a new frontier in the discovery and characterization of transients. While photometric light curves provi…
SN 2023zaw: an ultra-stripped, nickel-poor supernova from a low-mass progenitor
Kaustav K. Das, Christoffer Fremling, Mansi M. Kasliwal +34
We present SN 2023zaw a sub-luminous ( mag) and rapidly-evolving supernova ( days), with the lowest nickel mass (…
SN~2018erx: A fast-evolving, dust-reddened Type Icn supernova with broad C II emission lines
Kaustav K. Das, Anjasha Gangopadhyay, Mansi M. Kasliwal +17
We present the discovery and characterization of SN~2018erx (ZTF18abkmbpy), a fast-evolving, unusually red, interacting stripped-envelope supernova. Spectroscopically, SN~2018erx s…
Back from the dead: AT2019aalc as a candidate repeating TDE in an AGN
Patrik Milán Veres, Anna Franckowiak, Sjoert van Velzen +15
Context. To date, three nuclear transients have been associated with high-energy neutrino events. These transients are generally thought to be powered by tidal disruptions of stars…
ZTF25abjmnps (AT2025ulz) and S250818k: A Candidate Superkilonova from a Sub-threshold Sub-Solar Gravitational Wave Trigger
Mansi M. Kasliwal, Tomas Ahumada, Robert Stein +61
On August 18, 2025, the LIGO-Virgo-KAGRA collaboration reported gravitational waves from a sub-threshold binary neutron star merger. If astrophysical, this event would have a surpr…
An Extremely Luminous Flare Recorded from a Supermassive Black Hole
Matthew J. Graham, Barry McKernan, K. E. Saavik Ford +17
Since their discovery more than 60 years ago, accreting supermassive black holes in active galactic nuclei (AGN) were recognized as highly variable sources, requiring an extremely…
Cryoscope: A Cryogenic Infrared Survey Telescope in Antarctica
Mansi M. Kasliwal, Nicholas Earley, Roger Smith +58
We present Cryoscope--a new 50 deg field-of-view, 1.2 m aperture, survey telescope to be located at Dome C, Antarctica. Cryoscope has an innovative optical-thermal d…