44 terms

# Earth Science Chapter 3 Stars, Galaxies and the Universe

###### PLAY
Parallex
the apparent shift in an objects position when viewed from two locations
Universe
all of space and everything in it
Light-year
The distance that light travels in one year
Scientific Notation
Uses powers of 10 to write very large numbers or very small numbers in a shorter form.
Star
A giant ball of gas primarily hydrogen and helium
Planet
An object that orbits a star, is large enough to have become rounded by its own gravity and has cleared the area of its orbit.
Solar System
the system composed of the sun (a star) and the planets and other bodies that travel around the sun
Binary Star
a star system with two stars
Galaxy
large group of stars, dust, and gas held together by gravity; can be elliptical, spiral, or irregular
Spiral Galaxy
A galaxy with a bulge in the middle and arms that spiral outward in a pinwheel pattern.
Elliptical Galaxy
a galaxy shaped like a round or flattened ball, generally containing only old stars
Irregular Galaxy
a galaxy that does not have a regular shape
Quasars
an enormously bright, distant galaxy with a giant black hole at its center
Orbit
the path of an object as it revolves around another object in space
Force
a push or pull exerted on an object
Law of Universal Gravitation
the scientific law that states that every object in the universe attracts every other object
Mass
a measure of the amount of matter in an object
Weight
The measure of the force of gravity on an object.
Inertia
the tendency of an object to resist a change in motion.
Newtons first law of motion
an object in motion will remain in motion unless acted upon by another force
accretion
The process of building something up gradually by the gathering together of smaller pieces.
Spectrograph
an instrument that separates light into colors and makes an image of the resulting spectrum.
Apparent Brightness
the brightness of a star as seen from earth
Absolute Brightness
the brightness a star would have if it were at a standard distance from earth
Hertzsprung-russell diagram
a graph relating the surface temperatures and absolute brightness of stars
Main Sequence
a diagonal area on an H-R diagram that includes more than 90 percent of all stars
Nebula
a large cloud of gas and dust in space, spread out in an immense volume.
Proto star
A contracting cloud of gas and dust with enough mass to form a star.
White Dwarf
the blue-white hot core of a star that is left behind after its outer layers have expanded and drifted out into space.
Super Nova
The brilliant explosion of a dying supergiant star.
Neutron Star
the small, dense remains of a high-mass star after a supernova.
Pulsar
a rapidly spinning neutron star that produces radio waves
Black hole
an object whose gravity is so strong that nothing, not even light, can escape.
Core
The central region of the sun, where nuclear fusion takes place.
Nuclear Fusion
the process in which two atomic nuclei combine to form a larger nucleus, forming a heavier element and releasing huge amounts of energy.
a region of very tightly packed gas where energy is transferred mainly in the form of electromagnetic radiation.
Convection Zone
the outermost layer of the sun's interior.
Photosphere
The inner layer of the sun's atmosphere that gives off its visible light.
Chromosphere
the middle layer of the sun's atmosphere.
Corona
Outer layer of the sun's atmosphere.
Solar Wind
A stream of electrically charged particles produced by the sun's corona.
Prominence
A loop of gas that protrudes from the sun's surface, linking parts of sunspot regions.
Solar Flare
An eruption of gas from the sun's surface that occurs when the loops in sunspot regions suddenly connect.
Fun
violent and excited activity.