Exploring the universe Flashcards
Why do astronomers use lightyears to measure the distance of objects in space?
Because space is too big to use small measurments like kilometres.
Define nuclear fusion and it’s role when producing energy in the core of a main star.
Its when two small nuclei fuse to form a bigger nuclear, and when the energy that stars release forms hydrogen and which further form helium in a core of a main star. In the process the potential energy is converted into mass.
Explain what colour a star would be if the wavelength was approximately 840nm.
Because in a diagram of the visble spectrum the wavelength of this specific star would be off to the red side of the wavelengths.
Our galaxy…
is called the milky way and is a spiral shape.
What does the mass of a star tell us?
It’s absolute brightness.
What is the Big Bang Model
It’s the term used to describe the rapid expansion of the very early universe from a hot, dense concentration of matter.
Define Accreation
Accretion is defines as the process of growth of a body by gathering or aggregating more matter due to gravitational forces.
What are two peices of evidence that support the Big Bang model?
The red shift and cosmic microwaves background radiation.
When does a Protostar form?
When the gas of a nebula condenses, losing graviational potential energy and gainign kenetic energy, rasining the temprature of atoms.
What happens when theres fusion in the core of a protostar?
If the fusion of hyrdogen is big enough built in the core of a protostar then a main sequence star is formed.
What happens when the hydrogen in the main sequence star runs out?
It forms either a red giant or supergiant.
Why do white dwarfs form after red giants
Because when the fusion completly stops the gas breaks down, condensing into a small object called a white dwarf.
What is formed after a supergiant?
When the fusion stops in a supergiant the remaining energy explodes and creates a supernova.
What are the next steps after a supernova is formed?
If the remaining mass is smaller then 3 solar masses a neutron star is formed but if the remaining mass is larger than 3 solar masses then the black hole is created.
Order the suns colour from coldest to hottest.
red, yellow, white, blue
