Project:	Faint supernovae found in the overlapping footprints of the Zwicky Transient Facility and Rubin LSST surveys
Discipline:	Astronomy
Mentor:	Christoffer Fremling, Staff Astronomer, (PMA), fremling@caltech.edu
Background:	Modern time-domain surveys are transforming our view of stellar explosions by discovering supernovae at unprecedented rates and depths. The Zwicky Transient Facility (ZTF) has been operating for several years and has identified thousands of nearby supernovae, while the Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) will soon provide much deeper imaging over a large fraction of the sky. The overlap between these surveys offers a unique opportunity to study faint and rapidly evolving supernovae that may have been missed or poorly constrained by any single survey alone. In particular, some stripped-envelope supernovae (Type IIb) appear unusually faint, potentially indicating explosions that synthesize very little radioactive nickel. Understanding these events is important for constraining the final stages of massive-star evolution and the diversity of core-collapse supernova explosions.
Description:	The SURF student will work on a project focused on identifying and characterizing faint Type IIb supernovae discovered by ZTF, with an emphasis on objects that may also fall within the Rubin LSST survey footprint. The student will help build and test analysis workflows that merge ZTF and LSST data streams, including image data and multi-band light curves. They will select a small number of promising low-luminosity candidates, validate and refine the available photometric (and, where necessary, spectroscopic) data to a publication-ready state, and compare the observations to a grid of radiation-hydrodynamics supernova models generated with the SNEC code. For objects with LSST coverage, the student will incorporate deep late-time LSST imaging to improve constraints on explosion properties such as radioactive nickel mass, ejecta mass, and kinetic energy. The project will culminate in interpreting these results in the broader context of stripped-envelope supernovae.
Student Requirements:	Familiarity with working with astronomical data formats (.fits) Practical coding experience in Python, Matlab or adjacent languages
Programs:	This AO can be done under the following programs:   Program    Available To        SURF    both Caltech and non-Caltech students  Click on a program name for program info and application requirements.