Physics & Astronomy ETDs

Publication Date

Summer 7-28-2026

Abstract

This dissertation investigates how cold exoplanets can be identified despite the strong observational bias of exoplanet surveys toward short-period systems. Planets at wider orbital separations remain comparatively poorly constrained, limiting tests of planetary-system formation and the prevalence of outer architectures beyond compact systems. To address this gap, I use two complementary approaches. First, I develop a transit-search pipeline for TESS Full-Frame Images that identifies both isolated and repeated transit-like signals around nearby M dwarfs and characterizes the dominant false-positive classes that limit sensitivity in this regime. I then present TOI-904 c, the coldest planet discovered by TESS around an M dwarf to date, and Gaia23bra b, the first definitively identified gravitationally bound microlensing planet discovered with TESS. Together, these results expand the observational basis for studying cold planets and outer planetary architectures.

Degree Name

Physics

Level of Degree

Doctoral

Department Name

Physics & Astronomy

First Committee Member (Chair)

Diana Dragomir

Second Committee Member

Ylva Pihlström

Third Committee Member

Zachary Sharp

Fourth Committee Member

Jessie Christiansen

Language

English

Keywords

Astronomy, Exoplanets, Detection Techniques, Microlensing, Transits, Exoplanet Demographics

Document Type

Dissertation

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