PHYS 118 Intro Astronomy - Stars

A set of vocabulary flashcards based on key concepts in the lecture notes on stars from the Intro Astronomy course.

Luminosity

The total amount of energy emitted by a star per second, measured in Joules.

Brightness

A measure of how the energy in light is spread out across space; dependent on distance from the observer.

Intrinsic Property

A characteristic of a star that is inherent to the star itself, such as temperature, mass, and luminosity.

Relational Property

A characteristic of a star that depends on the observer’s perspective, such as distance and velocity.

Parallax

The apparent shift in position of a nearby star against distant background stars due to Earth's orbit.

Spectroscopy

A technique used to analyze the light spectrum emitted by stars, helping determine their composition and temperature.

Stefan-Boltzmann Law

A law relating the luminosity of a star to its radius and temperature.

Cepheid Variable

A type of star whose luminosity can be determined from its pulsation period, used as a standard candle for distance measurement.

Inverse Square Law

A principle stating that the brightness of a light source decreases with the square of the distance from the observer.

Mass-Luminosity Relation

The correlation that more massive stars tend to be more luminous.

Apparent Magnitude

The brightness of a star as it appears from Earth, affected by distance.

Absolute Magnitude

The brightness of a star as it would be observed from a standard distance of 10 parsecs.

Absorption Lines

Specific wavelengths of light absorbed by elements in a star's atmosphere, used to determine composition.

Proper Motion

The motion of a star across the sky over time, measured in arcseconds per year.

Standard Candles

Astronomical objects with known luminosity used to determine distances in space.

Velocity (Radial Motion)

The motion of a star moving towards or away from an observer, determined by Doppler shifts in spectral lines.