Stellar Astronomy and Star Life Cycles Flashcards

What is the Hertzsprung-Russell (H-R) diagram used to show?

Answer: The relationship between stellar luminosity and temperature

The H-R diagram plots stellar luminosity versus surface temperature, revealing that stars fall into distinct groups including the main sequence, giants, supergiants, and white dwarfs.

What powers a main-sequence star like the Sun?

Answer: Nuclear fusion of hydrogen into helium

Main-sequence stars are powered by nuclear fusion reactions in their cores, converting hydrogen into helium and releasing enormous amounts of energy via E=mc².

What stellar remnant is left after a low-mass star like the Sun ends its life?

Answer: White dwarf

After exhausting its nuclear fuel and shedding its outer layers as a planetary nebula, a low-mass star leaves behind a dense, hot white dwarf composed mainly of carbon and oxygen.

What is a neutron star?

Answer: An ultra-dense stellar remnant composed mainly of neutrons

A neutron star is an extremely dense stellar remnant formed from the collapsed core of a massive star after a supernova, with densities so extreme that protons and electrons merge into neutrons.

What is the Chandrasekhar limit?

Answer: The maximum mass (~1.4 solar masses) a white dwarf can have before collapsing

The Chandrasekhar limit (~1.4 solar masses) is the maximum mass a white dwarf can support against gravitational collapse; exceeding it leads to a Type Ia supernova.

What is a stellar parallax used to measure?

Answer: A star's distance from Earth

Stellar parallax measures the apparent shift in a star's position against background stars as Earth orbits the Sun, allowing astronomers to calculate the star's distance using trigonometry.