Quiz 2 study questions Flashcards
hyper nova is a GammaRay bursts source that is thought to correspond to the formation of a black hole with very focused bipolar Jets true or false
True
The escape speed for a black holes event horizon is the speed of light True or false?
True
The key to identifying a black hole Candidate in a binary system is to find an unseen compact companion that has a mass greater than the limiting mass of a neutron star true or false
True
The shcwarzshild of a black hole depends on its what?
Mass
When a star like the supergiant in the x-ray binary Cygnus x-1 fills its critical gravitationally bound surface. It will have the shape of a
Egg
What is a neutron stars limiting mass
3 solar masses
The black hole in Cygnus x-1 has a mass of_solar masses
15
Stars with a mass below 8% of the Suns of mass are called
Brown dwarfs
Stars with a mass below 8% slowly fade away because their cores are not hot enough to burn what element
Hydrogen
As stars Age their cores contract in their outer envelopes expands true or false
True
Following the completion of core hydrogen burning what would the sun turn into next
Red giant
What two elements do stars like the sun fuse together
He into carbon
A star like the sun will spend most of its nuclear life as a?
Main sequence star
The larger the stellar mass the longer the lifetime of the star true or false
False
Stars like the sun will shine by nuclear reactions for_years
10 billion
Evolution is different and close binary stars because stars can exchange some of their mass true or false
True
The sudden collapse of the iron core of a star into a compact ball of neutrons leads to a?
Supernova explosion
What is the upper limit for the mass of the white dwarf
1.4 solar masses
Type one nova always occur in a close binary system true or false
True
What is the likely progenitor of a type one supernova
A mass transfer binary
Stars form in dark clouds of dust and gas the gas between those stars is called?
Interstellar medium
What is interstellar medium
Gas between stars
What is a dark nebula
A cloud that obscures our view
What effect does interstellar dust have on stars
Makes them appear fainter and redder
True or false gravity can create stars if it can overcome the force of thermal pressure?
True
What would happen to a contracting cloud fragment if it were not able to radiate away it’s thermal energy?
Internal pressure would increase
A protostar becomes a main sequence star once the core becomes hot enough for nuclear fusion. True or false
True
Starlike objects massive enough to start fusion are called what
Brown dwarfs
In the mirror principle a core contracts because?
Pressure decreases when hydrogen is too low for fusion
When do subgiants become Giants?
When hydrogen is burning around a inert helium core. (Mirror principle)
When does the mirror principle begin
When most of hydrogen burning has ended
After hydrogen burns out what type of fusion begins to occur
Helium fusion
Hydrogen turns to helium and helium turns into what.
Carbon
After a multiple shell burning where many elements fuse in a shell the core of a star collapses and what happens?
A supernova explosion that leaves a neutron star or black hole
What is the white dwarf
The dead core of a star
A type 2 supernova is
The death or explosion of a massive star
A type one nova is
The explosion of WD which is half the size of earth in a binary
A neutron star is left behind by what
A massive star supernova or type 2
What is the radius of a neutron star
10 km or 6 miles
True or false all pulsars are neutron stars but not all neutron stars are pulsars
True
A GammaRay happens when two neutron stars merge or
A hyper nova occurs
When a star fills it’s critically gravitationally bound surface it begins to retain the shape of
An egg
