LERMA UMR8112

Laboratoire d’Études du Rayonnement et de la Matière en Astrophysique et Atmosphères



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LERMA UMR8112

Observatoire de Paris LERMA - UMR8112
77 avenue Denfert Rochereau - 75014 Paris

5 place Jules Janssen - 92190 MEUDON

4 place Jussieu Tour 32-33 - 3eme ET - 75005 Paris

Université de Cergy-Pontoise

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Credits

This website uses a graphic template that is designed and produced as part of the project for the harmonization of CNRS websites.

Project manager

Marco Cucchi (Pôle-web, DirCom, CNRS)

Web template development (Web team, Communications Department, CNRS)

  • Pascal Verrier: web development
  • Eric Furlan: web design and integration

Development of the plugin "Seminar"

Amaury Adon

Development of the initial versions of the template

Frank de Albuquerque - Jean-Baptiste Pressac (CNRS) - Valérie Pierre (CNRS) - Benoît Chassigneux - Julien Barnier (GRS) - Jean-Christophe Monferran (LAHIC) - Stéphane Pouyllau (CRHST)

CSS drop-down menu

Eric Meyer - http://more.ericmeyeroncss.com/projects/06/

Photo credits for the default banner

© CNRS Photothèque

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5.3.15

Logo SPIPKit made with SPIP (Internet publication system), free software published under GPL licence

Séminaires à venir

Vendredi 3 avril 2020, 14h00
Salle de l'atelier, Paris
The great dimming of Betelgeuse in 2019-2020
Miguel MONTARGES
KU Leuven, Institute of Astronomy
résumé :
Red supergiant stars are important contributors to the chemical enrichment of the Universe. Together with asymptotic giant branch stars, their lower mass counterpart, they contribute ~ 85% of gas and ~ 35% of dust to the total enrichment of the interstellar medium. Moreover, the stellar wind has a crucial impact on the final mass, hence on the nature of the compact remnant left after the supernova: a 20 solar mass star can loose up to 60% of its mass during its life. Yet the mechanism at the origin of the red supergiant mass loss remains unknown: there is no physical scenario to lift material from the photosphere up to the dust condensation zone where radiative pressure on small grains can drive the wind.

In November-December 2019, the prototypical red supergiant Betelgeuse started an impressive dimming that brought it to 37% of its average optical brightness in February 2020. It is dimmer than this star has been since quantitative magnitude measurements have been recorded (150 years). We have observed Betelgeuse at high angular resolution during this peculiar event with the VLT/SPHERE, VLTI/GRAVITY and VLTI/MATISSE instruments. I will present the first results of this multi-wavelength and multi-technique campaign and bring them in the context of the study of the red supergiant mass loss.
 
Vendredi 17 avril 2020, 14h00
Salle de l'atelier, Paris
Patricia TISSERA
Universidad Andres Bello, Santiago, Chili
 
Vendredi 24 avril 2020, 14h00
Salle de l'atelier, Paris
Tba
Philippe ANDRE
CEA
 
Tous les séminaires...