Types of stars Flashcards
What is temperature luminosity diagram?
Mass of star determines its temperature and luminosity
Hertzsprung Russel diagram
Where do most stars like on this diagram?
Lie on the main sequence running through centre of the diagram
Colour of hot and bright stars
Blue
Colour of cool and dim stars
Red
What is the stefan-Boltzmann Law?
Hotter ones are much brighter and bigger stars.
Distance to our sun
150 million Km
Mass of our sun
333,000 x Earth
Surface temp of sun
5800K
Age of our sun
4.6 billion years
Type of main Sequence of our sun
G-Type
What are sunspots?
Cooler regions in solar photosphere due to intense magnetic field strength
What is the stellar energy source?
Conversion of mass into energy known as nuclear fusion and proton-proton cycle
What is the proton-proton cycle?
He produced with two protons released to start cycle over.
How much energy is converted in the sun?
4.2 billion kg of mass every second
Why does proton-proton cycle work?
Mass of 4 protons is larger than mass of 1 helium atom
Total mass of the sun
2x10 30 kg
Lifetim of the sun
10 billion years
How are protons brought together?
Need to be within 10 -15m of each other fo fusion.
Need temperature above 10 million K for this to occur
Lifetime of a star relationship
More massive stars burn up very much quicker than objects like our sun.
Most common star type in Milky Way
K type - 5 billion
What is the relationship to find out its lifetime?
Lifetime = 1/(mass) power of 2.5
What is a brown dwarf?
Object with not enough mass to turn on the PP chain
What is the solar neutrino problem?
Models of the sun predict we need 2-3x higher neutrino flux than we observe
What are the explanations for the neutrino problem?
Neutrinos from PP chain are one of 3 types and they can change between these 3 types so hard to observe
When will life become unbearable from our sun?
1 billion years
How much larger do we expect our sun to get?
100x
