Unit 4 - Cosmology and stars

Front

What is the Doppler effect in relation to stars?

Back

The Doppler effect refers to the change in frequency or wavelength of light from a star due to its motion relative to an observer. If a star is moving toward us, its spectral lines are blueshifted, indicating shorter wavelengths.

Front

What is a Stellar Nebula?

Back

A Stellar Nebula is a cosmic cloud of dust and gas that serves as the first stage in the birth of a star. It is where the process of star formation begins.

Front

What does the H-R diagram represent?

Back

The Hertzsprung-Russell (H-R) diagram is a scatter plot of stars showing the relationship between their absolute magnitudes or luminosities versus their stellar classifications or effective temperatures.

Front

Which type of star is the hottest according to the H-R diagram?

Back

Type B stars are the hottest stars, characterized by their high temperatures and blue color.

Front

What is typically found at the center of a galaxy?

Back

A supermassive black hole is typically found at or near the center of a galaxy.

Front

What is the current understanding of the universe's expansion?

Back

The universe is currently understood to be expanding, as evidenced by the redshift of distant galaxies.

Front

Define blueshift in the context of astronomy.

Back

Blueshift is the phenomenon where light from an object moving toward an observer is shifted to shorter wavelengths, appearing bluer.

Front

What is a protostar?

Back

A protostar is an early stage in the formation of a star, where a cloud of gas and dust begins to collapse under gravity, leading to the formation of a dense core.

Front

What is a black hole?

Back

A black hole is a region in space where the gravitational pull is so strong that nothing, not even light, can escape from it.

Front

What is a red giant?

Back

A red giant is a late stage in the life cycle of a star, characterized by its large size and reddish color, resulting from the star's expansion and cooling.