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Je donne

Rechercher

Natural Sciences and Engineering

Nicole St-Louis

Wind structure of massive stars

Professeure titulaire

Faculté des arts et des sciences - Département de physique

Roger-Gaudry, room B405

514 343-6932

nicole.st-louis@umontreal.ca

Secondary email: stlouis@astro.umontreal.ca (Travail)

Profile

Research expertise

My research is mainly on the wind from the most massive stars. In view of their great luminosity - reaching one million times that of the Sun - these stars lose a large proportion of their mass over their lifetimes. This stellar wind is not symmetrical or homogenous. Not only does it contain small-scale inhomogeneities relating to turbulence, but in some cases also large-scale structures. These structures are particularly intriguing, since they are created by an as-yet unidentified mechanism occurring at the surface of the star.

The possible mechanisms include magnetic fields and pulses, two important physical processes in the evolution of massive stars, but about which we still have very little information.

The consequences of these large-scale structures for observable data (spectrum, photometry, polarization rate) can also help us to determine a fundamental parameter of these stars: their rotation velocity. This important detail is usually impossible to measure for the massive stars I am studying, since their surface is completely concealed behind the very dense wind. Because the large-scale structures are attached to the surface, identifying a period in the star's spectral or luminous variations lets us deduce the rotation velocity.

education

  • 1985 — Baccalauréat — PhysiqueUniversité de Montréal
  • 1987 — Maîtrise — PhysiqueUniversité de Montréal
  • 1990 — Doctorat — PhysiqueUniversity College London
  • 1993 — Post-doctorat — Astronomie et astrophysiqueUniversité de Montréal

Affiliations and responsabilities

Teaching and supervision

Student supervision

Theses and dissertation supervision (Papyrus Institutional Repository)

2019

Simulations Monte Carlo de régions d'interaction en corotation dans le vent d'étoiles chaudes

Graduate : Carlos-Leblanc, Danny
Cycle : Master's
Grade : M. Sc.
2016

A study of the large-scale structure of the wind of WR 134

Graduate : Aldoretta, Emily
Cycle : Master's
Grade : M. Sc.
2014

Étude de la variabilité spectroscopique d’un échantillon d’étoiles Wolf-Rayet de type WC9

Graduate : Desforges, Sébastien
Cycle : Master's
Grade : M. Sc.
2014

Recherche de champs magnétiques chez les étoiles Wolf-Rayet par l'analyse d'observations spectropolarimétriques.

Graduate : de la Chevrotière, Antoine
Cycle : Doctoral
Grade : Ph. D.
2009

Étude de l’étoile Wolf-Rayet variable WR 46 dans l’ultraviolet lointain et les rayons X

Graduate : Hénault-Brunet, Vincent
Cycle : Master's
Grade : M. Sc.

Projects

Research projects

2018 - 2024

Studying WolfRayet Stars Using Their Wind Structure and Circumstellar Nebula

Lead researcher : Nicole St-Louis
Funding sources: CRSNG/Conseil de recherches en sciences naturelles et génie du Canada (CRSNG)
Grant programs: PVX20965-(RGP) Programme de subvention à la découverte individuelle ou de groupe
2017 - 2024

Centre de recherche en astrophysique du Québec (CRAQ)

Lead researcher : Pierre Bergeron
Funding sources: FRQNT/Fonds de recherche du Québec - Nature et technologies (FQRNT)
Grant programs: PVXXXXXX-(RS) Programme de regroupements stratégiques
2016 - 2018

Centre de recherche en astrophysique du Québec (CRAQ)

Lead researcher : Pierre Bergeron
Funding sources: FRQNT/Fonds de recherche du Québec - Nature et technologies (FQRNT)
Grant programs: PVXXXXXX-(RS) Programme de regroupements stratégiques
2012 - 2018

THE WINDS OF WOLF-RAYET STARS : THEIR STRENGTH AND STRUCTURE

Lead researcher : Nicole St-Louis
Funding sources: CRSNG/Conseil de recherches en sciences naturelles et génie du Canada (CRSNG)
Grant programs: PVX20965-(RGP) Programme de subvention à la découverte individuelle ou de groupe
2008 - 2017

CENTRE DE RECHERCHE EN ASTROPHYSIQUE DU QUEBEC

Lead researcher : Pierre Bergeron
Funding sources: FRQNT/Fonds de recherche du Québec - Nature et technologies (FQRNT)
Grant programs: PVXXXXXX-(RS) Programme de regroupements stratégiques
2009 - 2013

Observatoire du Mont-Mégantic et laboratoire d'astrophysique expérimentale

Lead researcher : René Doyon
Co-researchers : Pierre Bergeron , Pierre Bastien , Claude Carignan , Daniel Nadeau , Nicole St-Louis

Outreach

Publications and presentations

Disciplines

  • Astronomy and Astrophysics

Areas of expertise

  • Fundamental astronomy
  • Fundamental aspects of astrophysics
  • Spectroscopy and spectrophotometry
  • Polarimetry
  • Time series analysis, time variability
  • Corotating streams
  • Circumstellar shells
  • Stellar rotation
  • Mass loss and stellar winds
  • Emission-line stars (Of, Be, LBV, Wolf-Rayet stars)