Brightness
What is a star?
It is a ball of burning gases that you see as a small point of light in the sky at night.
What is the color of a star related to?
the star's surface temperature
What is a variable star?
Stars that regularly or repeatedly change in magnitude
What is the smallest star group called?
What are asteroids?
irregularly shaped pieces of rocks, metal and dust
How do stars produce their own light?
What are the largest and brightest stars called?
Supergiants
What do pulsating variables go through?
periods of swelling and brightening; periods of shrinking and dimming
What do you call the star groups that have three or four stars? Provide an example (e.g. it is closest to Earth like the sun).
multiple star groups; Alpha Centauri
How big are most asteroids?
Most are as small as pebbles.
What is magnitude?
the brightness of a star
What is the general relationship between the size and magnitude of stars?
Larger stars have a brighter absolute magnitude.
When a star that exists gets bigger and becomes brighter than usual, what is it called?
Nova
How do astronomers classify a galaxy? What are the three they classify them into?
What causes a shooting star?
What is nuclear fusion?
Hydrogen atoms fuse together and form helium atoms. Then the star releases energy in the form of heat and light.
What do we call the apparent change in a star's movement over time that allows scientists to determine the star's distance from Earth?
Parallax
A neutron star (the collapsed core of a massive supergiant star) that spins quickly on its axis is called what?
Pulsar
What is the Local Group?
It is a cluster of galaxies, including the Milky Way, that travel together in space.
What is the main difference between meteoroid, meteor and meteorite?
A meteoroid is a rocky object in space that heads toward our atmosphere. As the friction of our atmosphere causes the rock to light up, we call it a meteor. If it then hits the Earth's surface, we call it a meteorite.
How do scientists determine a star's absolute magnitude?
They treat all the stars as if they were the same distance from Earth.
Other than the sun, what is the closest star to Earth?
Proxima Centauri
What is a nebula?
a cloud of dust, gases, and debris
Which other large galaxy is part of the Local Group?
Andromeda
A comet is an icy chunk of frozen gases, water and dust that orbits around the sun over and over again. What do some astronomers refer them to?
"dirty snowballs"