Astrophysics Lecture Notes

This set of flashcards summarizes important concepts from the lecture on astrophysics covering topics like stars, binary systems, fundamental forces, isotopes, and solar phenomena.

What is Weins Law used for?

It helps determine the peak temperature of a star.

What does luminosity depend on in stars?

Luminosity depends on the size and temperature of the star.

Define ground state in an atomic system.

The lowest possible energy state of a system.

What is the Emission Spectrum?

Atoms fall into lower energy states.

What does the Absorption Spectrum indicate?

Atoms jumping to higher energy states.

What are the spectral classes of stars?

OBA FG KM, where O is the hottest and M is the coolest.

How can Binary Systems be detected?

Through visual binaries, spectrobinaries, and eclipsing binaries.

What does an H-R diagram plot?

It plots the luminosities and surface temperatures of stars.

What percentage of stars spend their lifetime on the main sequence?

90% of stars spend their lifetime on the main sequence.

What is hydrostatic equilibrium?

It is when pressure and gravity are balanced.

List the four fundamental forces in the universe.

Strong force, electromagnetic force, weak force, and gravitational force.

What are isotopes?

Different forms of the same element with varying mass numbers.

What is a parsec?

A unit of distance defined as the distance to an object whose parallax angle is one second.

What is limb darkening?

The sun appears darker near the edge of the solar disk than near the center.

What is the primary element in the Sun?

The Sun is mostly composed of hydrogen.

What occurs during the proton-proton chain?

Two hydrogen nuclei collide, resulting in helium-3 and gamma radiation.

How long does it take for neutrinos to exit the sun?

Neutrinos escape the sun in about 2 seconds.

What is helioseismology?

The study of waves from the interior of the sun.