Calendar

Nov
8
mar
Comitech 08 @ Salle Chandon
Nov 8 @ 14 h 00 min – 16 h 00 min
Institutionnel
Nov
10
jeu
AG des projets @ Agora
Nov 10 @ 9 h 30 min – 17 h 00 min
Institutionnel
Nov
24
jeu
Codir 09 @ Salle Chandon
Nov 24 @ 10 h 00 min – 12 h 00 min
Institutionnel
Déc
6
mar
Comitech 09 @ Salle Chandon
Déc 6 @ 14 h 00 min – 16 h 00 min
Institutionnel
Déc
8
jeu
CLAB 05 @ Salle Univers
Déc 8 @ 9 h 30 min – 12 h 30 min
Institutionnel
Déc
15
jeu
AG de Noël @ Salle Univers
Déc 15 @ 9 h 30 min – 14 h 30 min
Institutionnel
09:30 – accueil café en salle Univers
10:00-12:00 – présentations sur le thème de l’histoire de l’observatoire et du laboratoire (thème à confirmer) en salle Univers
12:30-14:30 – déjeuner festif au restaurant La Passerelle (https://www.crous-bordeaux.fr/restaurant/restaurant-la-passerelle/)
Jan
10
mar
AG du Nouvel an @ Salle Univers
Jan 10 @ 9 h 30 min – 15 h 30 min
Institutionnel
09:30-10:00 – accueil café
10:00-12:30 – présentations de la Direction et de SAFIRH
12:30-14:30 – créneau libre pour le déjeuner selon les modalités habituelles des personnels
14:30-15:30 – galette, boissons et vœux de bonne année
Jan
12
jeu
Laurent Chemin – Dynamics of the Milky Way and LMC as seen by Gaia @ B18N, Salle Chandon (306)
Jan 12 @ 11 h 00 min – 12 h 30 min
Séminaire

Speaker : Laurent Chemin (Universidad Andres Bello, Instituto de Astrofisica)

Title: Dynamics of the Milky Way and LMC as seen by Gaia

Abstract: 

Six months have passed since the Third Release of data from Gaia, the billion star surveyor of ESA. In this talk, I will present recent results obtained by the Gaia Collaboration with Gaia DR3 on the stellar dynamics of the Milky Way and the Large Magellanic Cloud. I will also describe how Gaia is changing our understanding of the evolution of the Local Group from the analysis of the orbits of dwarf galaxies around our Galaxy.

 

Jan
17
mar
Philippe Bonneton – Tidal bore dynamics in estuaries @ B18N, Salle Univers
Jan 17 @ 11 h 00 min – 12 h 30 min
Séminaire

Speaker : Philippe Bonneton (EPOC, CNRS/U. Bordeaux)

Title: Tidal bore dynamics in estuaries

Abstract:  A tidal bore is a sudden elevation of the water surface that travels upstream an estuary with the incoming flood tide. The formation and dynamics of this spectacular and fascinating phenomenon bring into play nonlinear wave interactions over a large range of spatiotemporal scales. A tidal bore is a small-scale estuarine process with scales of variation of order few seconds in time and dozen meters in space. This small-scale process, which generally occurs in the upper estuary, results from the nonlinear transformation of the tidal wave over long distance (several dozen of kilometers) and long period of time (several hours). The general bore phenomenon has been extensively studied in fluid mechanics and mathematics. On the other hand, the large-scale mechanisms which control tidal bore formation has so far received little attention. In this presentation we will analyze tidal bore formation from a unique long term database acquired during 4 campaigns in the two main French tidal-bore estuaries: the Seine and Gironde/Garonne estuaries. We will show that the tidal bore intensity is mainly governed by the dimensionless tidal range, which characterizes the local tidal wave nonlinearity. We will also show that the undular bore structure can be explained by two different wave processes depending on the bore intensity.

Jan
24
mar
Camille Bergez-Casalou – Simultaneous accretion of giant planets or how giant planets fight for food @ B18N, Salle Univers
Jan 24 @ 10 h 30 min – 12 h 30 min
Séminaire

Speaker : Camille Bergez-Casalou (LESIA)

Title: Simultaneous accretion of giant planets or how giant planets fight for food

Abstract:  Among the thousands of exoplanetary systems observed nowadays, some of them host multiple giant planets, like in our Solar System. These giants are probably formed from the same protoplanetary disc. I’m going to present our recent paper where we investigated, with the help of 2D hydrodynamical simulations, how the gas present in the protoplanetary disc is distributed and accreted by two planetary cores. We start with 20 Me cores undergoing runaway gas accretion and follow the evolution of the planets mass ratio. We find that when the planets accrete from the same disc, they end up with very similar masses, independently on the disc viscosity or the delay in accretion between the planets. We finish by suggesting different formation scenarios in order to explain the observed exoplanets distribution.