What are the properties of the 400+ exoplanets we have discovered so
far? This lecture reviews the properties of exoplanets, and finds a
couple of surprises: Jupiter-mass planets orbiting close to their parent
stars, and Jupiter-mass planets in very elliptical orbits. Both seem to
require some mechanism for migration: strong gravitational interactions
wit ... Show More
Sep 2009
Lecture 2: Astronomical Numbers
An introduction and review of the basic notation and physical units we will be
using throughout this course. In particular, we will be using the
Metric (SI) system for lengths, masses, times, and temperatures, and
special astronomical units for distances (AU and Light Years) and ... Show More
43m 56s
Mar 2022
Comment calculer l'âge d'une étoile ?
La durée de vie d'une étoile peut nous renseigner sur sa composition et sur l'existence éventuelle de la vie dans le cosmos. mais, en dehors du Soleil, il est assez difficile de déterminer l'âge d'une étoile.
L'importance de la masse
En évaluant, grâce à la radioactivité, l'âge d ... Show More
1m 58s