49:45 duration 49 minutes 45 seconds
ASTR 1523 Lecture 10
50:28 duration 50 minutes 28 seconds
ASTR 1523 Lecture 9
49:56 duration 49 minutes 56 seconds
ASTR 1523 Lecture 8
50:10 duration 50 minutes 10 seconds
ASTR 1523 Lecture 7