Collaborative Research: Pinning down the source of the L/T transition with the help of polarimetry.

Brown dwarfs, often referred to as "failed stars," occupy a fascinating middle ground between stars and planets. As these objects age, they undergo a dramatic transformation known as the L/T transition, during which their atmospheres and observed properties change rapidly. This transition is crucial for understanding the evolution of brown dwarfs, as well as for drawing parallels with many imaged exoplanets, which often resemble these brown dwarfs. This research team will illuminate the mysteries of the L/T transition using the technique of polarimetry. Graduate and undergraduate students will gain hands-on experience in modeling, observation, and data analysis. The team will also develop educational resources, including a website and interactive tools, to engage and inform high school and university students about polarimetry and its applications in astrophysics. The L/T transition in brown dwarfs is marked by rapid atmospheric changes that affect their color and variability in light. This project seeks to address the underlying causes of these changes by using polarimetry to provide new constraints on the models of brown dwarf atmospheres. The research will involve creating a comprehensive grid of models that incorporate both cloud formation and chemical processes, assessing their impact on both flux and polarization signals. This grid will be instrumental in interpreting both existing and new polarimetric observations. The primary goals are to refine the understanding of the L/T transition and to develop tools that will aid in the design and analysis of future polarimetric observations of brown dwarfs and exoplanets. The project includes a significant training component, supporting two graduate students and 1-2 undergraduates annually at UCF, JHU, and UCSB. The team will develop a dedicated website and educational materials to promote the technique of polarimetry and its applications, thereby fostering greater engagement with the broader scientific community and the public. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.