Project:	Projects in planetary and stellar astronomy
Disciplines:	Astronomy, Astrophysics
Mentor:	Yinuo Han, Barr Fellow, (GPS), yinuo@caltech.edu
Mentor URL:	https://yinuohan.github.io  (opens in new window)
Background:	Multiple opportunities for summer projects in astronomy are available, which lie broadly in the fields of exoplanets and stars. Projects range from observations and data inference to theoretical modelling. You are welcome to get in touch if you are interested in working within the group and we can discuss projects based on your interests. In the field of exoplanets, the past few decades of observational efforts have revealed that planets and belts of planetesimals, which are familiar to us in the Solar System, are common around stars. Images of these extrasolar planetesimal belts, also known as debris disks, have shown that they exhibit a range of observable structures, such as gaps, asymmetries and warps, which are shaped by the formation and evolution history of the planetary system, as well as any ongoing interactions with planets in regions where they are difficult to detect. In the field of stars, high resolution imaging has in recent decades revealed the detailed structure of dusty nebulae formed from the collision of stellar winds launched by Wolf-Rayet stars. These are the most massive stars that are nearing the end of their evolution before becoming core-collapse supernovae. The website linked above provides some background, with a few papers relevant to specific projects listed below.
Description:	Projects are available to use images of debris disks to understand the dynamical conditions in planetary systems or to computationally model the geometry of the disk shaped by both intrinsic evolution and perturbing planets. Projects could make use of data from a range of premier observatories, including but not limited to the James Webb Space Telescope (JWST) and the Atacama Large Millimeter Array (ALMA), or could take a more theoretical or computational approach, depending on the interest of the student. Projects are also available to examine and model JWST, ALMA or data from other observatories on the intricate dust structures of Wolf-Rayet stars imaged at a range of wavelengths to better understand their physical properties, mechanisms of production and subsequent evolution.
References:	Some papers on exoplanet systems and imaging their disks • ALMA images a sample of debris disks at unprecedented resolution: https://www.aanda.org/articles/aa/full_html/2026/01/aa56489-25/aa56489-25.html, revealing diverse structures https://www.aanda.org/articles/aa/full_html/2026/01/aa56450-25/aa56450-25.html • An elusive clump of dust and gas inhabits the debris disk in an alien planetary system, and work is still ongoing to figure out which way it is moving, if at all: https://academic.oup.com/mnras/article/519/3/3257/6960576 • The James Webb Space Telescope provided a sharp view of a dusty disk in another alien planetary system at mid-infrared wavelengths: https://arxiv.org/abs/2601.15285 Some papers on imaging exquisite dust structures from massive stars • Tracking the expansion of a dusty nebula after its production by a violent duo of massive stars: https://www.nature.com/articles/s41586-022-05155-5 • The James Webb Space Telescope revealed a long but regular history of dust production demonstrated by eerie ring-like structures: https://www.nature.com/articles/s41550-022-01812-x • The colliding-wind binary Apep produces spiral-shaped dust shells that are among the most intricately structured known to stellar physics: https://iopscience.iop.org/article/10.3847/1538-4357/ae12e5
Student Requirements:	• A background in physics and/or astronomy • Programming experience (Python) • Interested in further study in astronomy
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.