Stellar wind variability in OB stars and its effect on mass-loss determinations
Abstract
Virtually all stellar winds of OB stars exhibit variability in one spectral diagnostic or another. This review focuses primarily on UV spectroscopic signatures of this variability and on studies that have exploited it to reveal the presence of large-scale velocity and density structures in the winds. The review includes demonstrations that the physical structures responsible for the variations appear to be large, spatially coherent and rooted in the stellar photospheres. Furthermore, evidence is summarised that these structures can be optically thick to resonance line radiation and are dense enough to modulate the X-ray fluxes that originate in the wind. Also discussed, is how the structures can affect wind line formation and, as a result, the precision by which mass-loss rates can be determined. The potential of millimetre and radio continuum observations to constrain the radial stratification of wind clumping is highlighted, as a future path to reliable empirical determinations of massive star mass-loss rates.
Related
- The variable mass-loss in low-mass red giant stars. Chromospheric motion across stellar evolution in 47 Tuc
- Population synthesis of low-mass binaries with wind-accreting neutron stars
- The origin of dispersion in the wind mass-loss rate--luminosity relation of massive O stars
- The origin of dispersion in the wind mass-loss rate–luminosity relation of massive O stars
- Migration Traps as Variability Attractors. II. Nonmonotonic X-Ray Timing Signatures of Embedded Stellar-Mass Black Holes in AGN Disks
BibTeX
@misc{prinja2026stellar,
title = {{Stellar wind variability in OB stars and its effect on mass-loss determinations}},
author = {Raman K. Prinja},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.03363},
eprint = {2611.03363},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.03363},
}
RIS
TY - UNPB
TI - Stellar wind variability in OB stars and its effect on mass-loss determinations
AU - Raman K. Prinja
PY - 2026
DA - 2026/11/02
PB - arXiv
DO - 10.48550/arxiv.2611.03363
UR - https://arxiv.org/abs/2611.03363
AB - Virtually all stellar winds of OB stars exhibit variability in one spectral diagnostic or another. This review focuses primarily on UV spectroscopic signatures of this variability and on studies that have exploited it to reveal the presence of large-scale velocity and density structures in the winds. The review includes demonstrations that the physical structures responsible for the variations appear to be large, spatially coherent and rooted in the stellar photospheres. Furthermore, evidence is summarised that these structures can be optically thick to resonance line radiation and are dense enough to modulate the X-ray fluxes that originate in the wind. Also discussed, is how the structures can affect wind line formation and, as a result, the precision by which mass-loss rates can be determined. The potential of millimetre and radio continuum observations to constrain the radial stratification of wind clumping is highlighted, as a future path to reliable empirical determinations of massive star mass-loss rates.
ER -