Stellar Evolution and Stellar Remnants

These flashcards cover key concepts from the lecture on stellar evolution and remnants, designed to help you review and prepare for your exam.

What is a star?

A self-luminous, gravitationally bound, ball of gas that shines or has shone because of nuclear reactions in its interior.

What is the definition of binary stars?

Multiple systems bound by gravity and orbiting each other.

What is a nebula?

An enormous volume of dust and gas where stars form.

What is a proto-star?

A young star that is still in the process of formation.

What occurs in hydrostatic equilibrium in a star?

As temperature in the interior rises, nuclear reactions produce an outward force that balances the inward force of gravity, stabilizing the star.

What is the process of hydrogen fusion in stars?

Four hydrogen nuclei fuse to become one helium nucleus, converting leftover mass to energy as described by E=mc².

What is the relationship between a star's mass and its lifetime?

The more massive a star, the faster it consumes its fuel and the shorter its lifetime.

What are the end stages of low mass stars like our Sun?

They evolve into a red giant, then into a planetary nebula, and finally become a white dwarf.

What defines a red supergiant?

A massive star in old age, characterized by multiple fusion shells (e.g., hydrogen, helium, carbon) before becoming a supernova.

What happens to the core of a star after a supernova explosion if its mass is between 1.4 and 3 times that of the Sun?

It turns into a neutron star.

What happens to the core of a supernova if its mass is between 3 and 10 times that of the Sun?

It becomes a black hole.

What will happen to the outer layers of our Sun when it reaches its old age?

It expands as a planetary nebula.