Stars Flashcards
(31 cards)
What process causes stars to shine?
Nuclear fusion in their cores.
What are the primary components of stars?
Hydrogen and helium.
What conditions in a star’s core enable nuclear fusion?
High pressure and heat.
What happens during nuclear fusion in the Sun?
Two hydrogen atoms fuse to form a helium atom.
What is required to initiate the fusion process?
High energy.
What do fusion reactions produce once they start?
More energy.
How are stars classified?
Based on their color and corresponding temperature.
What color indicates a cool star?
Red.
What color indicates an extremely hot star?
Blue or blue-white.
What does the color of a star indicate?
Its surface temperature.
What classification letter corresponds to blue stars?
O.
What classification letter corresponds to red stars?
M.
Where do stars form?
In clouds of gas and dust called nebulas.
What is an example of a nebula with star-forming regions?
The Orion Nebula.
What occurs during the process of star formation?
Gravity pulls gas and dust to the center of the nebula.
What happens when the temperature in a forming star is high enough?
Nuclear fusion begins.
What defines a star in the main sequence stage?
Hydrogen atoms fuse into helium in its core.
How long do medium-sized stars like the Sun shine?
Approximately 10 billion years.
How long do large stars remain in the main sequence?
About 10 million years.
What happens when a star like the Sun runs out of hydrogen?
It begins to fuse helium.
What is the result when a star enters the red giant stage?
It becomes a larger, cooler star with a red color.
What happens to a star after it becomes a red giant?
It shrinks into a white dwarf.
What is a white dwarf?
A small, hot, white, and glowing remnant of a star.
What is a red supergiant?
A massive star that fuses heavier elements.
