About Us
We are the Massive Star Group at Armagh Observatory, specializing in the wind physics of massive and very massive stars in the local Universe as well as the metal-poor early Universe. Our expertise spans stellar evolution modeling and hydrodynamical atmosphere modeling, enabling us to study stellar winds, mass loss, and the cosmic feedback of the most massive stars.
Group Lead
Professor Jorick S. Vink is a leading astronomer at Armagh Observatory whose models of radiation-driven winds in massive stars have significantly advanced our understanding of stellar wind physics, stellar feedback, chemical enrichment, and the distribution of black hole masses. His research interests include the physics of stellar winds and stellar evolution, with a particular focus on the role of radiation pressure at the upper end of the stellar mass spectrum. On the observational side, much of his work involves spectroscopy and spectro-polarimetry. He also leads the XShooting ULLYSES consortium aimed at obtaining optical and near-IR spectra for hundreds of massive stars in the Magellanic Clouds to complement the UV spectra from ULLYSES.
Current and Past Team Members
- Ciaran Furey – PhD Student
- Ethan Winch – PhD Student
- Gautham Sabhahit – Postdoctoral Researcher
- Erin Higgins – Former Postdoctoral Researcher
- Andreas Sander – Former Postdoctoral Researcher
Research Highlights from the group
Theory and Diagnostics of Hot Star Mass Loss
Vink (2022) reviews advances in hot star wind theory, highlighting complex dependencies of mass loss on stellar parameters and metallicity. The work discusses wind transitions across the HR diagram and identifies very massive and stripped helium stars as key ionizing sources shaping star formation locally and at high redshift.
Maximum black hole mass across cosmic time
Vink et al. (2021) demonstrate that very massive stars at low metallicity can produce black holes exceeding the pair-instability limit (~50 M⊙) by accounting for core overshooting and metallicity-dependent winds. Their MESA models explain gravitational wave detections of heavy black holes (~85 M⊙) and map maximum BH masses as a function of metallicity and cosmic time.
Predicting the heaviest black holes below the pair instability gap
Winch et al. (2024) challenge the traditional pair-instability mass gap by showing that blue supergiant progenitors with small cores but massive hydrogen envelopes at low metallicity can produce black holes up to ~93 M⊙. Using an extensive grid of MESA models with varying physics, they demonstrate how mixing and envelope retention fill the lower PI gap, impacting predictions for heavy BH formation.
Mass-loss implementation and temperature evolution of very massive stars
Sabhahit et al. (2022) develop a new MESA mass-loss recipe transitioning between O-star and Wolf-Rayet winds, showing that VMS mass loss scaling with luminosity-to-mass reproduces the observed narrow temperature range in Galactic and LMC very massive stars. This reveals a self-regulatory mechanism stabilizing their effective temperatures during evolution.
Massive star evolution: rotation, winds, and overshooting vectors in the mass-luminosity plane
Higgins & Vink (2019) present a calibrated grid of rotating massive star models constrained by the eclipsing binary HD 166734. Their mass-luminosity plane tool requires enhanced core overshooting and rotational mixing to match observations, implying a widened main sequence and influencing red supergiant luminosities and supernova explodability.
Recent Publications
- The impact of wind mass loss on nucleosynthesis and yields of very massive stars at low metallicity
Higgins et al. (2025), arXiv e-prints - The black hole - pair instability boundary for high stellar rotation
Winch et al. (2025), MNRAS - A new mass estimate method with hydrodynamical atmospheres for very massive WNh stars
Sabhahit et al. (2025), Astronomy and Astrophysics
Contact
Email: Prof. Jorick Vink