Key Concepts in Stellar Remnants and Galactic Phenomena

These flashcards cover essential vocabulary and definitions related to stellar remnants, galaxies, and cosmological concepts.

White Dwarf

A stellar remnant that is the remaining core of a low to intermediate mass star, characterized by an electron-degenerate state, high temperature, and low luminosity.

Neutron Star

An extremely dense stellar remnant composed almost entirely of neutrons, formed by the gravitational collapse of a massive star during a supernova.

Black Hole

A region of spacetime exhibiting gravitational acceleration so strong that nothing can escape from it, formed from the remnants of a massive star after a supernova.

Chandrasekhar Limit

The maximum mass (approximately 1.4 solar masses) that a white dwarf can have before it becomes unstable and collapses under its own gravity.

Event Horizon

The boundary surrounding a black hole beyond which no information or matter can escape, marking the point of no return.

Galaxies Classification

Galaxies are mainly classified into three types: spiral, elliptical, and irregular, based on their shape and structure.

Cosmic Distance Ladder

A series of methods by which astronomers determine the distances to celestial objects, using different techniques that build upon each other.

Hubble's Law

A formulation in astronomy that states that the recessional velocity of galaxies is proportional to their distance from us, indicating the expansion of the universe.

AGN (Active Galactic Nucleus)

A region at the center of some galaxies that is exceptionally bright and is believed to be powered by a supermassive black hole accreting matter.

Cosmic Microwave Background (CMB)

The thermal radiation filling the universe, a remnant from the Big Bang, with a temperature of approximately 2.7 Kelvin, providing evidence for the early state of the universe.