Time-domain astrophysics, supernovae, gamma-ray bursts (GRBs), transient surveys, and open-source software — supported by the Rutherford Postdoctoral Fellowship, Marsden Fast Start, and a NASA ADAP grant.
My group works in time-domain astrophysics, using space telescopes like TESS, JWST, and Roman to catch cosmic explosions as they happen. We build open-source pipelines that mine these archives for transients no one was looking for — from supernovae and the fast, hour-scale flashes of gamma-ray burst afterglows to interstellar visitors passing through the Solar System. Alongside the software, we run dedicated all-sky surveys and follow up the most unusual events with spectroscopy, training the next generation of transient astronomers in the process.
The three most recent papers from the group.
The first hour-scale extragalactic optical transient with fully resolved evolution — from explosion through decay — caught by TESS. Found via the HiLaTS program in an interacting galaxy pair at z = 0.67, AT 2020afjz rises over ~1 hr and lasts just 2.4 hr above half-max. Modelling favours a dirty-fireball or orphan afterglow interpretation.
The first superluminous Type IIn supernova caught on the rise with TESS photometry. Led by PhD student Zac Lane — a spatial and temporal coincidence with X-ray transient GRB191117A (3.3σ) points to shock breakout into a dense, asymmetric circumstellar medium.
Rapid spectroscopic characterisation of 3I/ATLAS — only the third interstellar object ever detected passing through the Solar System. The featureless, steeply red optical spectrum provides baseline data for monitoring this visitor as it approaches the Sun.
Active collaborations across the world — from STScI and Harvard to Swinburne, Arizona, and beyond.
Full list also on ORCID.
Reports the first hour-scale extragalactic optical transient with fully resolved evolution from explosion through decay observed by TESS. Discovered through the HiLaTS program and associated with an interacting galaxy pair at z = 0.67, AT 2020afjz rises over ~1 hr and remains above half-max brightness for only 2.4 hr. Its brightness and duration resemble gamma-ray burst afterglows; modelling supports a dirty-fireball or orphan afterglow classification, though a gamma-ray non-detection could not be confirmed due to satellite occlusion.
Introduces TESSreduce, an open-source Python package for reducing TESS space telescope data with a focus on preserving short-lived transient signals. The pipeline performs background subtraction, image alignment and differencing, and flux calibration to physical units via PS1 and SkyMapper cross-matching. TESSreduce is now the standard tool for community transient science with TESS, with 27 GitHub stars and 15 forks.
Presents starkiller, an open-source Python pipeline for removing stellar and satellite contamination from integral field unit (IFU) spectroscopic datacubes. The tool forward-models catalog stars using Gaia DR3 data, extracts PSFs from the data itself, and performs spectral matching against stellar libraries — enabling clean observations of extended objects like comets, asteroids, and galaxies.
A systematic search through all archival Kepler/K2 data for previously undetected background transients. By developing custom difference-imaging techniques tailored to Kepler's unique pixel scale, this survey pioneered the approach of mining space telescope data for serendipitous transient discoveries that laid the groundwork for TESSELLATE.
Reports the discovery and characterisation of a rare WZ Sagittae-type cataclysmic variable system using the Kepler K2 mission. K2's unbroken light curves revealed the system's outburst structure and orbital dynamics in unprecedented detail.
Uses archival TESS observations to search for rotational brightness variations in one of the largest known Oort cloud comets, observed at record distances from the Sun (21–24 au). No detectable rotational signal was found, placing constraints on its surface heterogeneity.
The first detailed study of a gamma-ray burst captured in high-cadence optical photometry by TESS. The 10-minute cadence light curve revealed a late optical peak more than 1000 seconds after the initial gamma-ray trigger, enabling estimates of the jet Lorentz factor (90–133).
The most comprehensive search to date for gamma-ray burst optical afterglows in TESS data. Led by student Hugh Roxburgh, this work systematically cross-matched all GRB triggers with TESS full-frame images, characterising the unique constraints TESS provides on GRB optical emission timescales.
The first superluminous Type IIn supernova caught on the rise with well-sampled TESS photometry. Led by PhD student Zac Lane, with a striking spatial and temporal coincidence with the X-ray transient GRB191117A (3.3σ confidence). The TESS light curve constrains first light to within 7.2 hours and reveals shock breakout into a dense, asymmetric circumstellar medium from a luminous blue variable progenitor.
A landmark detection of optical precursor emission from a massive star in the 130 days before it exploded as a Type II supernova. Direct observational evidence that stars undergo substantial envelope inflation and enhanced mass loss in their final months before death.
Multi-facility detection of AT2022cmc, one of the most luminous tidal disruption events ever observed — a relativistic jet pointing directly at Earth, ~100× brighter than typical TDEs and visible at cosmological distances.
Detailed optical photometry of GRB 221009A — the "BOAT" (Brightest Of All Time). Disentangles the rapidly fading afterglow from a flux excess consistent with an emerging Type Ic supernova from the star that exploded to create this record-breaking GRB.
Comprehensive documentation of NASA's DART mission — the first demonstration of kinetic impact as a planetary defence technique. The spacecraft changed Dimorphos's orbital period by 33.24 minutes, proving humanity can redirect an asteroid.
International campaign finding BlueWalker 3 reached peak magnitude 0.4 — bright enough to see with the naked eye — quantifying the severe threat that large commercial satellite constellations pose to ground-based optical and radio astronomy.
Rapid spectroscopic characterisation of 3I/ATLAS, only the third interstellar object ever detected. The featureless, steeply red optical spectrum suggests a dust-rich coma with no detectable gas emission at the time of discovery, providing baseline data for monitoring this visitor as it approaches the Sun.
TESS captured SN 2021zny just 5.3 hours after explosion, revealing an early flux excess inconsistent with standard Type Ia models. Combined with late-time oxygen emission, the data support a double white dwarf merger origin.
Led by PhD student Zac Lane, this reanalysis of the Pantheon+ catalogue finds the first evidence that timescape cosmology may provide a better overall fit than ΛCDM, opening a new data-driven window on dark energy alternatives.
Statistical analysis of Type Ia supernova data provides strong evidence that the timescape cosmology fits the Pantheon+ data better than the standard ΛCDM model, challenging foundational assumptions about dark energy.
TESS's 10-minute cadence captured an early optical excess in the first day after explosion of SN 2023bee — a brief blue bump invisible to ground-based surveys, constraining the explosion mechanism and companion interaction.
Presents TESSELLATE, a dedicated pipeline for untargeted all-sky searches for variable and transient phenomena in TESS data to magnitude 17, deployed at supercomputer scale on OzSTAR.