Twinkle Little Star Flashcards
What is a star?
A star is a luminous celestial object made up of hot plasma, held together by its own gravity. Stars are the fundamental building blocks of galaxies and the primary sources of light and energy in the universe.
Why do stars twinkle
atmosphere refracts starlight in random directions very quickly
Blue Stars:
Blue stars are among the hottest and most massive stars. 30,000 kelvin
White Stars
They have high surface temperatures, typically ranging from 7,500 to 10,000 Kelvin
Yellow Stars:
have a surface temperature around 5,500 Kelvin.
Orange Stars
They have lower surface temperatures compared to yellow stars, typically ranging from 3,500 to 4,500 Kelvin.
Stars have different brightnesses primarily due to two factors:
their distance from Earth and their intrinsic luminosity.
The intrinsic luminosity of a star refers to the
total amount of energy it emits per unit of time. (brighter = higher)
distance
F=L/(4πd^2 ) or F=σT4(R2/d2)
Stefan-Boltzmann Law
L=4πR^2 σT^4 R = Radius, o = constant, T = surface temperature
Dwarf Stars
dwarf stars are small and relatively common. They can have radii ranging from about 0.1 to 10 times the radius of our Sun
Main Sequence Stars
Main sequence stars, like our Sun, fall into a broad range of sizes. They can have radii ranging from less than half the radius of the Sun to many times larger.
Giant and Supergiant Stars:
As stars evolve, some of them expand and become significantly larger. radii 10 times sun
Neutron Stars:
Neutron stars are extremely dense stellar remnants that form after the explosion of massive stars in supernova events.
What are HR diagrams?
A way of showing how stars relate by
temperature and luminosity – a way of
understanding their evolution.
