HW 9: Stars and Adolescence to Old Age

If the rate of fusion in the star's interior depends on the fourth power of temperature, by what factor should the fusion reaction increase when the temperature of the star’s core doubles?

16 times

As hydrogen fuses to form helium, which of the following changes happens in the star’s core?

Energy increases, density increases, composition increases, and luminosity increases

On what main factor does the lifetime of a star depend?

Rate of fusion

In the hunt for exoplanets, which type of stars should we focus on and why?

G type, because they live long enough

Which of the following is an open star cluster?

Pleiades

What is the mass limit, also known as Chandrasekhar limit, for a star to end as a white dwarf?

1.4 solar mass

What is the type of pressure that halts gravitational core collapse in a white dwarf?

Electron degeneracy pressure 

What does the core of a white dwarf keep collapsing until its density increases until core collapse stops? 

The mass of a star is too small for gravity to generate sufficient gas pressure to counter gravity

What happens to a star with core mass greater than 1.4 solar masses 

It has a completely different fate determined by the core mass.

How dense is the core of a neutron star?

10 trillion times earth’s density

What are pulsars?

Rapidly spinning neutron stars

Who discovered pulsars?

Jocelyn Bell

What is a type 1 supernova?

Smaller white dwarfs accreting matter from its companion main sequence star and going over the Chandrasekhar limit, resulting in its explosion.

For what value of core mass, does a black hole form, unable to resist the gravitational collapse and getting compressed to an infinitely small volume and reaching infinitely densities?

3 solar mass 

Precise determination of location via GPS satellite is a practical application of which famous theory?

General theory of relativity

What is the velocity at which an object can overcome the gravitational pull of a heavier object called?

Escape velocity

The radius of the event horizon, or the surface of no return, was derived by the German theoretical physicist, Karl Schwarzschild. What does the expression for the radius tell us?

Radius of event horizon is larger for larger stellar mass

Name the largest detector that is currently employed in gravitational wave detection of black hole merger events 

LIGO

Planetary nebulae are misnomers. Previously observers had thought they resembled planetary disks and named them so. What are they really?

Eruptions from Red Giants