This large cloud of gas and dust is where stars form.
What is a nebula?
Our Sun is classified as this type of star by mass.
What is a medium-mass star?
Stars are classified by color, temperature, size, and this type of brightness.
What is absolute brightness?
A galaxy shaped like a pinwheel with arms is called this.
What is a spiral galaxy?
A system with two stars orbiting each other.
What is a binary star system?
Gravity pulls gas and dust together to form this early stage of a star.
What is a protostar?
This stage occurs when a medium star expands and cools near the end of its life.
What is a red giant?
This is how bright a star appears when viewed from Earth.
What is apparent brightness?
A rounded or oval-shaped galaxy is called this.
What is an elliptical galaxy?
When one star passes in front of another and blocks its light, it forms this system.
What is an eclipsing binary?
This process begins when hydrogen atoms fuse to create energy and a star officially forms.
What is nuclear fusion?
After the red giant stage, the outer layers of the star form this cloud of gas.
What is a planetary nebula?
To calculate absolute brightness, astronomers need apparent brightness and this measurement.
What is distance from Earth?
This galaxy type has no regular shape.
What is an irregular galaxy?
This word describes everything that exists including all galaxies and matter.
What is the universe?
This force pulls gas and dust together during star formation.
What is gravity?
The leftover hot core of a medium star after the planetary nebula stage.
What is a white dwarf?
The color of a star tells scientists about this property.
What is temperature?
Our solar system is located in this galaxy.
What is the Milky Way galaxy?
This system includes the Sun and everything that orbits it.
What is the solar system?
When nuclear fusion begins, a protostar becomes this type of object.
What is a star?
After a supernova, the star may collapse into one of these extremely dense objects.
What is a neutron star or black hole?
Blue stars are generally this compared to red stars.
What is hotter?
This type of active galaxy has a supermassive black hole at its center.
What is a quasar?
Stars are made mostly of these two gases.
What are hydrogen and helium?