Physics 105 Flashcard 2: Stellar Evolution and Navigation

Front

What is a Neutron Star?

Back

A neutron star is the remnants of a supernova explosion, composed almost entirely of neutrons, and is incredibly dense, with a mass greater than that of the Sun but a radius of only about 10 kilometers.

Front

What is Right Ascension in astronomy?

Back

Right Ascension (RA) is a coordinate in the celestial coordinate system that measures the angle of an object eastward along the celestial equator from the vernal equinox, typically measured in hours, minutes, and seconds.

Front

How many hours of Right Ascension are there on the Celestial Sphere?

Back

There are 24 hours of Right Ascension on the Celestial Sphere.

Front

Where is the Sun located on the H-R diagram?

Back

The Sun is located on the Main Sequence of the H-R diagram.

Front

What is the mass threshold for a star to become a Brown Dwarf?

Back

A star must have less than 0.08 solar masses (M☉) to become a Brown Dwarf.

Front

What is the H-R diagram?

Back

The Hertzsprung-Russell diagram (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

What is a White Dwarf?

Back

A white dwarf is a small, dense star that is the remnant of a low or medium mass star that has exhausted its nuclear fuel and shed its outer layers.

Front

What is a Brown Dwarf?

Back

A brown dwarf is a substellar object that is too massive to be considered a planet but not massive enough to sustain hydrogen fusion reactions in its core, typically having a mass between 13 and 80 times that of Jupiter.

Front

What is the significance of the Main Sequence in stellar evolution?

Back

The Main Sequence is the stage in a star's life where it fuses hydrogen into helium in its core, representing the longest phase of a star's life cycle.

Front

What happens to a star after it exhausts its hydrogen fuel?

Back

After exhausting hydrogen fuel, a star may expand into a red giant, and depending on its mass, it can shed its outer layers to form a planetary nebula or explode as a supernova.