IB PHYSICS Option D: Astrophysics

Solar System

Includes the Sun, planets, moons, asteroids, and comets within our system.

Binary Star

Two stars orbiting a common center.

Dark Matter

Cold, non-radiating matter inferred from physics.

Main Sequence Star

A normal star undergoing hydrogen fusion to become helium.

Lightyear

Distance light travels in a year in space vacuum, approximately 9.461 × 10^12 kilometers.

Stellar Parallax

Measures space distances using Earth's orbit.

Luminosity

Total power radiated by a star in all directions, measured in watts.

Inverse Square Law

States a physical quantity is inversely proportional to the square of the distance from the source.

Hertzsprung–Russell (HR) Diagram

Relates absolute magnitude, luminosity, classification, and temperature of stars.

Chandrasekhar Limit

Maximum mass for a white dwarf, about 1.4 solar masses.