ASTR Final Exam Flashcards

Why are stars visible to the naked eye considered atypical?

They are generally much brighter than typical stars and are often not found in proximity to the Sun.

What are the categories of Binary Stars?

Visual Binary and Spectroscopic Binary.

What does the mass-luminosity relationship indicate?

More massive stars are more luminous, following the relation L ∝ M^4.

What processes define the life cycle of low mass stars?

Nebula, Main Sequence, Red Giant, Planetary Nebula, White Dwarf.

What are the main components of the Sun's structure?

Core, Radiative Zone, Convective Zone, and Atmosphere (Photosphere, Chromosphere, Corona).

What causes the apparent motion of stars across the sky?

The rotation of the Earth from west to east.

What is the measure of how bright a star appears from Earth?

Apparent brightness, which depends on both luminosity and distance.

What is the significance of the Hertzsprung-Russell diagram?

It plots stars according to temperature and luminosity, illustrating their classification.

What is the importance of Cepheid variable stars?

They are used as standard candles for measuring astronomical distances due to their predictable brightness variability.

What occurs during a supernova?

A massive star explodes, ejecting its outer layers and leaving behind a neutron star or black hole.

What is the definition of escape velocity?

The speed needed to break free from an object's gravitational pull.

How do heavy stars end their life cycle?

They undergo a supernova explosion, leaving behind a neutron star or a black hole depending on their mass.

What is gravitational redshift?

The increase in the wavelength of light from an object moving away from an observer, indicating it is losing energy.

What types of stars primarily form in emission nebulae?

Young stars, specifically those of type O and B.

What is the main factor that distinguishes red dwarfs?

They are cooler and dimmer main sequence stars.

How do astronomers measure distances in space?

Using methods like stellar parallax, Cepheid variables, and Type Ia supernovae.

What is the role of neutron degeneracy pressure?

It supports neutron stars against gravitational collapse.

What happens in a binary system to trigger a white dwarf supernova?

A white dwarf accumulates mass from a companion star until it exceeds 1.4 Msun, leading to a collapse.

What are the phases of star formation?

Collapse of dense cores in molecular clouds, formation of protostars, and eventual star development.

What is a stellar nursery?

Regions where new stars are born, typically found in the spiral arms of galaxies.