Senior Research Associate · University of Cambridge

Leigh Smith

I work on wide-field time-domain and astrometric surveys, exoplanet transit detection, and near-infrared stellar astrometry. I build efficient, scalable software for analysing massive astronomical datasets — from individual light curves to catalogues of a billion stars.

About

Research interests

My work spans wide-field time-domain and astrometric surveys, exoplanet transit detection, stellar occultations, and Galactic structure. I have a particular interest in low-mass stars and brown dwarfs — especially thick disk, halo, and benchmark examples — and in completing the census of the solar neighbourhood.

I enjoy the challenges of working with and analysing massive datasets, and writing efficient, scalable code. My current work at the Institute of Astronomy, Cambridge, focuses on GPU-accelerated transit detection for ESA's PLATO mission and near-infrared astrometry with VIRAC.

Languages
Python SQL Bash C/C++ CUDA PHP JavaScript
Libraries & frameworks
NumPy SciPy Astropy Numba PyCUDA Scikit-learn Pandas Matplotlib PostgreSQL MySQL
Methods & tools
Distributed computing MPI Machine learning Bayesian inference Time-series analysis FITS / HDF5 Git
Projects
01

CETRA — GPU-accelerated exoplanet transit detection

Development of a CUDA GPU-based transit detection pipeline incorporated into the ESA PLATO Exoplanet Analysis System. CETRA implements an optimised Box Least-Squares approach with adaptive frequency grids and parallelised execution, designed to operate at survey scale across the full PLATO photometric dataset. Work also includes GPU-accelerated transit light curve modelling and modelling of ring systems around exoplanets.

CUDA / GPU Transit Detection BLS ESA PLATO Python
GitHub
02

VIRAC — VVV Infrared Astrometric Catalogue

Production of a world-leading catalogue of stellar proper motions in the near-infrared Milky Way, derived from 14 terapixels of VISTA/VVV imaging. The pipeline processes over 100 billion detected objects, cleans the catalogue, and produces photometric and astrometric time series for over one billion stars. Proper motions are derived via robust regression and used to study Galactic structure, identify thick-disk and halo members, and mine for periodic variables using supervised machine learning.

VVV / VISTA Proper Motions Galactic Structure ML Classification PostgreSQL MPI
VVV
03

Stellar occultation light curve analysis

Bayesian analysis of light curves from stellar occultations, with a focus on irregularly shaped objects in the outer solar system. Probabilistic shape modelling to constrain the physical properties of occulting bodies from high-cadence photometric observations.

Bayesian Inference Light Curves Solar System Python
04

Publications

Peer-reviewed papers, conference proceedings, and preprints. See my NASA ADS or arXiv author page for a full list.

arXiv NASA ADS
arXiv
Experience & Education
Sept 2022 – present
University of Cambridge

Senior Research Associate

GPU-accelerated exoplanet transit detection and light curve modelling (CUDA) for the ESA PLATO mission.
Transit modelling of exoplanets hosting ring systems.
Geometric and intensity distortion calibration for Euclid and VISTA instrumentation.
Oct 2017 – Aug 2022
University of Cambridge

Research Associate

Extraction, cleaning, and time-series production for over 1 billion stars from 14 terapixels of semi-structured infrared imaging (VISTA/VVV).
Robust regression analysis of astrometric time series to produce VIRAC, a world-leading near-IR proper motion catalogue of the Milky Way.
Mining for periodic pulsating stars using supervised ML classification (scikit-learn).
Bayesian analysis of stellar occultation light curves; probabilistic shape modelling.
Supervision of graduate and postgraduate students in survey data mining and neural-network-based source extraction.
Extensive use of Python, NumPy, SciPy, PostgreSQL, MPI, and BeeGFS distributed storage.
Oct 2015 – Sept 2017
University of Hertfordshire

Research IT System Manager

Administration and support of the UH high-performance computing cluster and associated infrastructure.
Development of PHP-based user-facing web tools for MySQL databases.
Numerical analysis of large-scale stellar survey data.
2011 – 2015
University of Hertfordshire

PhD Astrophysics

Development of software for highly accurate geometric distortion correction of astrophysical images.
Measured proper motions for millions of stars, identifying over a thousand nearby objects in the solar neighbourhood.
2008 – 2011
University of Hertfordshire

BSc Astrophysics

Graduated with first class honours and the Robert Jack Prize for outstanding undergraduate performance.

Contact

I'm based at the Institute of Astronomy, University of Cambridge. Open to research collaborations, conference invitations, and software work in the astronomical domain.