61 citations · 297 across the 29 of their papers we have counts for
24 papers · 1 filter
Mapping Wolf-Rayet winds with spectro-interferometry I. Detection of multiple co-rotating interaction regions in WR 6
K. Deshmukh, A. -N. Chené, A. J. Frost +8
WR 6 is the prototype for periodic variability due to large-scale wind structures in Wolf-Rayet (WR) stars, showing a consistent periodicity of 3.76 d in photometry, spectroscopy,…
Distinct Population of Wolf-Rayet Stars in the Low-Metallicity Galaxy NGC 6822. Quantitative analysis of optical and UV spectra of the complete sample
R. Trigg, L. M. Oskinova, W. -R. Hamann +9
Context: Wolf-Rayet (WR) stars are particularly rare in low-metallicity galaxies and remain poorly understood. Detailed studies of the presumably complete population of WR stars in…
The complex dependencies of Wolf-Rayet winds -- Insights from detailed radiative transfer models
Andreas A. C. Sander, Roel R. Lefever, Gemma González-Torà
With their emission-line dominated spectra, the appearance of Wolf-Rayet stars is shaped by their strong stellar winds. Yet, the physical mechanisms behind their high mass loss hav…
Dynamically consistent analysis of Galactic WN4b stars
Roel R. Lefever, Andreas A. C. Sander, Matheus Bernini-Peron +6
Many Wolf-Rayet (WR) stars have optically thick winds that cloak the hydrostatic layers of the underlying star. In these cases, traditional spectral analysis methods are plagued by…
EWOCS-V: Is Wd1-72 a recent post-interaction WR+O binary?
C. J. K. Larkin, J. Mackey, H. Jin +14
The evolutionary origin of Wolf-Rayet (WR) stars at Solar metallicity is unclear. Single-star evolution from massive O stars, possibly via a Luminous Blue Variable phase, is challe…
Interferometry of Massive Stars: Multiplicity, Magnetism, and Stellar Winds
H. Sana E. Bordier, K. Deshmukh, A. J. Frost +7
After decades of efforts, optical long-baseline interferometry has become a mainstream observational technique in terms of operation robustness and user friendliness. Interferometr…
A high fraction of close massive binary stars at low metallicity
H. Sana, T. Shenar, J. Bodensteiner +74
At high metallicity, a majority of massive stars have at least one close stellar companion. The evolution of such binaries is subject to strong interaction processes, heavily impac…
Discovery of a new transitional type of evolved massive stars with hard ionizing flux
Andreas A. C. Sander, Roel R. Lefever, Joris Josiek +12
Wolf-Rayet (WR) stars are the evolved descendants of the most massive stars and show emission-line dominated spectra formed in their powerful stellar winds. Marking the final evolu…
Near-Eddington mass loss of hydrogen-rich Wolf-Rayet stars
Roel R. Lefever, Andreas A. C. Sander, Matheus Bernini-Peron +6
Context. Very massive clusters and regions of intense star formation such as the center of our Milky Way contain young, hydrogen-burning stars very close to the Eddington Limit. Fo…
Improving 1D stellar atmosphere models with insights from multi-dimensional simulations II. 1D versus 3D hydrodynamically consistent model comparison for WR stars
G. González-Torà, A. A. C. Sander, N. Moens +8
Classical Wolf-Rayet (cWR) stars are evolved massive stars that have lost most of their H envelope and exhibit dense, extended atmospheres with strong, line-driven winds. Accuratel…
Exploring the connection between atmosphere models and evolution models of very massive stars
Joris Josiek, Andreas A. C. Sander, Matheus Bernini-Peron +6
Very massive stars (VMS) dominate the light of young stellar populations and are sources of intense stellar feedback. Their evolution is mainly driven by strong wind mass loss, yet…
New empirical mass-loss recipe for UV radiation line-driven winds of hot stars across various metallicities
D. Pauli, L. M. Oskinova, W. -R. Hamann +7
The winds of massive stars remove a significant fraction of their mass, strongly impacting their evolution. As a star evolves, the rate at which it loses mass changes. In stellar e…
Coupling hydrodynamics with comoving frame radiative transfer. III. The wind regime of early-type B hypergiants
M. Bernini-Peron, A. A. C. Sander, F. Najarro +8
Context. B hypergiants (BHGs) are important for understanding high-mass stellar evolution. While they are in a similar parameter space of B supergiants (BSGs), some BHGs are known…
A new mass estimate method with hydrodynamical atmospheres for very massive WNh stars
Gautham N. Sabhahit, Jorick S. Vink, Andreas A. C. Sander +4
Very massive stars with masses over 100 Msun are key objects in the Universe for our understanding of chemical and energetic feedback in the Universe, but their evolution and fate…
X-Shooting ULLYSES: massive stars at low metallicity: XII. The clumped winds of O-type (super)giants in the Large Magellanic Cloud
Sarah A. Brands, Frank Backs, Alex de Koter +23
Mass loss governs the evolution of massive stars and shapes the stellar surroundings. To quantify the impact of the stellar winds we need to know the exact mass-loss rates; however…
Improving 1D stellar atmosphere models with insights from multi-dimensional simulations I. 1D vs 2D stratifications and spectral comparison for O stars
G. González-Torà, A. A. C. Sander, J. O. Sundqvist +7
We compare current 1D and multi-dimensional atmosphere modelling approaches for massive stars to understand their strengths and shortcomings. We calculate averaged stratifications…
Investigating 39 Galactic Wolf-Rayet stars with VLTI/GRAVITY: Uncovering A Long Period Binary Desert
K. Deshmukh, H. Sana, A. Mérand +16
Wolf-Rayet stars (WRs) are one of the final evolutionary stages of massive stars and immediate progenitors of stellar-mass black holes. Their multiplicity forms an important anchor…
X-Shooting ULLYSES: Massive stars at low metallicity. IV. Spectral analysis methods and exemplary results for O stars
A. A. C. Sander, J. -C. Bouret, M. Bernini-Peron +26
CONTEXT: The spectral analysis of hot, massive stars is a fundamental astrophysical method to obtain their intrinsic properties and their feedback. Quantitative spectroscopy for ho…
Binarity at LOw Metallicity (BLOeM): a spectroscopic VLT monitoring survey of massive stars in the SMC
T. Shenar, J. Bodensteiner, H. Sana +74
Surveys in the Milky Way and Large Magellanic Cloud revealed that the majority of massive stars will interact with companions during their lives. However, knowledge of the binary p…
X-Shooting ULLYSES: massive stars at low metallicity. I. Project Description
Jorick S. Vink, A. Mehner, P. A. Crowther +78
Observations of individual massive stars, super-luminous supernovae, gamma-ray bursts, and gravitational-wave events involving spectacular black-hole mergers, indicate that the low…
X-Shooting ULLYSES: Massive stars at low metallicity. III. Terminal wind speeds of ULLYSES massive stars
C. Hawcroft, H. Sana, L. Mahy +26
The winds of massive stars have an impact on stellar evolution and on the surrounding medium. The maximum speed reached by these outflows, the terminal wind speed, is a global wind…
Exploring the influence of different velocity fields on Wolf-Rayet star spectra
Roel R. Lefever, Andreas A. C. Sander, Tomer Shenar +3
Given their strong stellar winds, Wolf-Rayet (WR) stars exhibit emission line spectra that are predominantly formed in expanding atmospheric layers. The description of the wind vel…
The temperature dependency of Wolf-Rayet-type mass loss: An exploratory study for winds launched by the hot iron bump
A. A. C. Sander, R. R. Lefever, L. G. Poniatowski +3
CONTEXT: The mass loss of He-burning stars, which are partially or completely stripped of their outer hydrogen envelope, is a catalyst of the cosmic matter cycle and decisive ingre…
Investigating the impact of different velocity fields on the spectral appearance of Wolf-Rayet stars
Roel R. Lefever, Tomer Shenar, Andreas A. C. Sander +3
The emission line spectra of WR stars are often formed completely in the optically thick stellar wind. Hence, any assumption on the wind velocity law in a spectral analysis has a p…