STELLAR BIRTH
What is the primary ingredient for the birth of stars?
Hydrogen Gas
What is the longest and most stable phase in a star's life?
Main sequence phase.
What is the fate of low-mass stars, like our Sun, at the end of their lives?
They become white dwarfs.
What is an astronomical phenomenon known as spaghettification?
The stretching and elongation of an object, like a star, as it approaches and falls into a black hole due to tidal gravitational forces.
What is the final state of a low-mass star, and what is left behind?
A white dwarf, leaving behind a planetary nebula.
During stellar birth, what collapses to form a protostar?
A nebula or molecular cloud
What is the primary source of energy for a star during its main sequence phase?
Nuclear fusion of hydrogen into helium.
What is the primary force responsible for a planetary nebula's expansion?
Stellar winds.
Contrast gravitational redshift with the redshift observed due to the Doppler effect.
Gravitational redshift occurs due to gravity's influence on light, while Doppler redshift is caused by the motion of a light source away from an observer.
Explain why neutron stars are sometimes observed as pulsars.
Pulsars result from the emission of beams of radiation along the magnetic axis, causing periodic pulses as the star rotates.
In what region do stars typically form within a galaxy?
Define the main sequence turnoff point in a star cluster.
The point on a Hertzsprung-Russell diagram where stars leave the main sequence and evolve into giants.
Describe the process that leads to a type 2 supernova.
Iron ore collapses due to the exhaustion of nuclear fuel.
Why is there no gravitational blue shift counterpart to gravitational redshift?
Gravitational blue shift is not observed because photons lose energy as they climb out of a gravitational well.
Why do high-mass stars undergo a supernova explosion?
Due to core collapse when the star exhausts its nuclear fuel and the core is made up of mostly inert iron.
What critical factor initiates the process of star formation in a molecular cloud?
Shockwaves from nearby supernovae
What happens to a star when it exhausts its core hydrogen fuel?
It expands into a red giant or supergiant.
What determines whether a high-mass star will become a neutron star or a black hole?
The mass of the collapsing core.
How do astronomers study black holes in binary systems?
By observing the effects of the black hole's gravity on its companion star, such as accretion disks and X-ray emissions.
Discuss the concept of neutron degeneracy pressure and its role in stellar remnants.
Neutron degeneracy pressure supports neutron stars against gravitational collapse, preventing them from becoming black holes.
Explain the role of shockwaves in triggering the collapse of a molecular cloud.
Shockwaves compress the molecular cloud, leading to gravitational collapse and star formation.
Explain the significance of the Hertzsprung-Russell (H-R) diagram in understanding stellar lifetimes.
The H-R diagram helps classify stars based on their luminosity, temperature, and evolutionary stage.
How does a type 1 supernova differ from a type 2 supernova?
Type 1 is a result of the explosion of a white dwarf in a binary system, while type 2 is from the collapse of a massive star.
Briefly explain the concept of gravitational waves and their role in understanding celestial events.
Gravitational waves are ripples in spacetime caused by the acceleration of massive objects. They provide a new way to observe and study cosmic events, such as mergers of black holes or neutron stars.
Why is it challenging to observe black holes directly?
Black holes do not emit light, making them challenging to observe directly. Their presence is inferred through the effects of their gravity on nearby matter.