The exoplanet sulfur shoreline
We use a coupled VULCAN–PICASO framework to study how atmospheric chemistry and radiative–convective structure jointly shape the distribution of sulfur-bearing species across exoplanet environments.
Undergraduate researcher · National Taiwan University
Cheng-An Hsieh
Planetary atmospheres & exoplanets
Summer 2025
Caltech SURF Research FellowYuk Group · PI: Yuk L. Yung
2023–2027
B.S. in PhysicsNational Taiwan University · expected June 2027
2025–2027
Undergraduate Research AssistantAcademia Sinica Institute of Astronomy and Astrophysics (ASIAA) · PI: Shang-Min Tsai
Summer 2026
Caltech SURF Research FellowKnutson Group · PI: Heather A. Knutson
I study how planetary environments shape atmospheric chemistry, thermal structure, and atmospheric escape. I connect models and observations in both directions: simulations predict measurable signatures, while observations test those predictions and reveal missing physics.
Current research
Current projects span coupled atmospheric chemistry and climate, upper-atmosphere escape, and transport in Solar System and exoplanet atmospheres.
Atmospheric escape from WASP-33 b
We model the upper atmosphere of the ultra-hot Jupiter WASP-33 b to investigate atmospheric escape and compare synthetic metastable-helium absorption with observations.
Middle-atmosphere chemistry on Venus
We develop a microphysical condensation–evaporation model within a two-dimensional chemical-transport framework, coupling atmospheric dynamics, aerosol transport, and photochemistry to investigate the vertical D/H profile in Venus’s middle atmosphere.
The atmosphere of WASP-193 b
We use VULCAN with coupled radiative-transfer modeling to investigate how deep energy deposition reshapes the thermal structure and chemical composition of WASP-193 b, and how those changes may appear in JWST observations.
Previous research
Earlier projects in extragalactic astronomy and small-body science developed the observational and computational perspective that now informs my planetary-atmosphere research.
Obscured black-hole accretion history
Using JWST/MIRI CEERS sources to investigate the growth history of obscured active galactic nuclei.
Read the PASA paperIdentifying binary asteroids
Developing simulated light curves and machine-learning approaches to identify binary asteroids in survey data.
Publications, abstracts & presentations
Research articles and conference contributions are listed separately to make publication status clear. A fuller record of research and public talks is available on the presentations page.
Peer-reviewed publication
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2025
Inferring obscured cosmic black hole accretion history from AGN found by JWST/MIRI CEERS survey
C.-A. Hsieh, T. Goto, C.-T. Ling, S. J. Kim, T. Hashimoto, T. C.-C. Chien, and A. Y.-A. Chen
Publications of the Astronomical Society of Australia, 42, e095
Conference abstract
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2025
The Influence of Transport on Chemistry in the Middle Atmosphere of Venus
C. A. Hsieh, T. J. Liao, F. P. Mills, C. D. Parkinson, and Y. L. Yung
AGU Fall Meeting Abstracts
Selected research presentations
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2026
The Influence of Aerosol-Driven Transport on the D/H Stratification in the Middle Atmosphere of Venus
Oral presentation · ASROC Annual Meeting
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2026
Modeling Atmospheric Chemistry of the Ultra-Low-Density Exoplanet WASP-193 b
Oral presentation · ASROC Annual Meeting
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2026
Modeling Atmospheric Chemistry of the Ultra-Low-Density Exoplanet WASP-193 b
Poster · Annual Meeting of the Physical Society of Taiwan · Poster Award (Honorable Mention)
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2025
The Influence of Transport on Chemistry in the Middle Atmosphere of Venus
Oral presentation · AGU Fall Meeting
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2025
Identifying Binary Asteroids Using Machine Learning with Simulated Lightcurves and FOSSIL Survey Data
Poster · Annual Meeting of the Astronomical Society of the Republic of China
Awards, fellowships & programs
A concise selection of research, academic, outreach, and earlier science awards.
Poster Award — Honorable Mention
Annual Meeting of the Physical Society of Taiwan
Caltech SURF BaBar Fellow
Summer Undergraduate Research Fellowship
Student Altruism Award
National Taiwan University
Outstanding Undergraduate Thesis — Honorable Mention
Taiwan Physical Society
TAOVA Summer Research Internship
Summer research program
Silver Medal
International Earth Science Olympiad (IESO)
Science communication & writing
Research is one part of how I engage with science. I also organize astronomy education, give public talks, and write science and fiction for broader audiences.
Hoshiko Plan
Expanding access to STEM through astronomy and nature education in rural communities.
- Founder
- Nonprofit STEM education initiative
- Astronomy- and nature-based learning programs
Public Science Talks
Selected public talks on astronomy and planetary science.
- Astronomy, Asteroids, and Falling in Love
Astronomy Clubs & Student Association
Leading astronomy organizations to foster community engagement.
- President, HCHS Astronomy Club (Sep. 2020–Present)
- President, NTU Astronomy Club
- Vice President, Student Association of Physics Department (Sep. 2023–Jun. 2025)
- Organizer of stargazing events and observational campaigns
Science Communication
Writing and sharing knowledge to inspire curiosity in astronomy.
- Popular-science articles for Science Monthly, Taiwan’s longest-standing popular-science magazine
- First Prize, NTU Literature Award — Short Story Category
EASY Team Member
Contributing to the EASY astronomy and Earth science outreach team.
- Published astronomy and Earth science articles on social media
- Developed public-facing science content
Creative Writing
Short fiction recognized in Taiwanese literary competitions.
- First Prize, NTU Literary Award
- Newcomer Award, United lifestyle
Contact me
For research questions, collaborations, or opportunities, email me or explore my public work and code.