Chapter 11: Stars and galaxies in the Universe Flashcards
What is the definition of a galaxy?
A set of bodies consisting millions of stars with gas and dust particles
State the 3 forms of galaxy.
- spiral
- elliptical
- irregular
Gives some examples for spiral galaxy
- Andromeda
- The Milky Way
Give some examples for elliptical galaxy
- Ursa Major
- Messier 87
Give some examples of irregular galaxy
- Small Magellanic Cloud
- Large Magellanic Cloud
What is The Milky Way?
a medium large spiral galaxy
Where is our solar system located in The Milky Way?
edge of one of the spiral arms of The Milky Way
How many stars consist in the milky way?
ard 200 billion
How are stars ‘borned’?
The gases and dust particles in a nebula are pulled by strong gravatitional force to form a globe, shrinks and compress it till it becomes less dense, which became a core. The core continues to shrink and becomes dense due to the increasing strength in gravatitional force. When the temperature and pressure in it become too high, a nuclear reaction will take place, releasing a huge amount of heat energy and light. Then, it’ll shine.
What is a nebulae?
large clouds consisting of dust particles and gases
What will the new star becomes if continued being expanded?
either average star or massive star
How do stars ‘die’?
When a lot of heat is generated, hydrogen within the outermost layer will start to burn, causing the star expand and appearing red in colour which is called a red giant. If it’s not massive, a white dwarf is formed. If it’s massive, it contracts quickly and a big explosion called supernova occurs, forming a neutron star (large star) or blackhole (super-large star)
Why is black hole called black hole?
light cannot escape it, neither do anything
What are the characteristics of stars?
CT Scan 不懂 stars (CTSBD)
- colour
- temperature
- size
- brightness
- distance
From what colour to what colour is the hottest to the coolest of the temperature of stars?
Red→orange→yellow→yellowish white→bluish white→blue
its like fire
