AST221H1 Lecture Notes - Lecture 5: Reduced Mass, Doppler Effect, Escape Velocity
17 Sep 2019
School
Department
Course
Professor
Document Summary
1 one body revolving another one at the focal point of the system. The motion is described using kepler"s laws, we have been focusing on this problem so far. 2 binary systems, revolving around a common center of mass. Example: pluto and charon (its moon) have similar masses, so they revolve around a common point as a binary system. 3 multiple bodies system example: solar system, galaxies and star clusters. Binary stars optical/apparent not actually binary, not bound to each other, have independent motion but from our point of view it looks like they form a binary system. Physical binaries actually bound gravitationally orbit a common centre of mass visual/astrometric resolved, can map the motion with astrometry. Eclipsing orbital plane coincides or almost coincides with line of sight. The system is perceived through light curves and usually is unresolved. Spectroscopic unresolved, detected by seeing 2 distinct signature spectrum lines. Seeing their doppler shift can determine the motion between them.
