Chapter 25 Vocaulary Flashcards

Front 1

Absolute Magnitude

Back 1

Measure of the amount of light a star actually gives off

Front 2

Apparent Magnitude

Back 2

Measure of the amount of light from a star that is received on Earth

Front 3

Big Bang Theory

Back 3

States that about 13.7 billion years ago, the universe began with a huge fiery explosion

Front 4

Black Hole

Back 4

Final stage in the evolution of a very massive star, where the core's mass collapses to a point that it's gravity is so strong that not even light can escape

Front 5

Chromosphere

Back 5

Layer of the Sun's atmosphere above the photosphere

Front 6

Constellation

Back 6

Group of stars that forms a pattern in the sky that looks like a familiar object (Libra), animale (Pegasus), or character (Orion)

Front 7

Corona

Back 7

Outermost, largest layer of the Sun's atmosphere, 0065tends millions of kilometers into space and has temperatures up to a 2 million K

Front 8

Galaxy

Back 8

Large groups of stars, dust, and gas held together by gravity; can be elliptical, spiral or irregular

Front 9

Giant

Back 9

Late stage in the life of comparatively low-mass main sequence star which hydrogen in the core is deleted, the core contracts and temperatures inside the star increase, causing its outer layers to expand and cool.

Front 10

Light-Year

Back 10

Unit representing the distance light travels in one year - about 9.5 trillion km - used to record distances between stars and galaxies

Front 11

Nebula

Back 11

Large cloud of gas and dust that contracts under gravitational force and breaks apart into smaller pieces, each of which might collapse to form a star

Front 12

Neutron Star

Back 12

Collapsed core of a supernova that can shrink to about 20km in diameter and conatins only neutrons in the dense core

Front 13

Photosphere

Back 13

Lowest layer of the Sun's atmosphere; gives off light and has temperatures of about 6,000 K

Front 14

Sunspot

Back 14

Area on the Sun's surface that are cooler and less bright than surrounding areas, are caused by the Sun's magnetick field, and occur in cycles

Front 15

Supergiant

Back 15

Late stage in the life cycle of a massive star in which the core heats up, heavy elements form by fusion, and the star expands; eventually explode to form a supernova

Front 16

White Dwarf

Back 16

Late stage in the life cycle of a comparatively low-mass main sequence star; formed when its core dep-letes its helium and its outer layers escape into space, leaving behind a hot dense core

Front 17

Bionary System

Back 17

A system consisting of or marked by two things or parts; such as a system with two suns

Front 18

Parallax

Back 18

The difference in apparent direction of an object as seen from two different points not on a straight line with the object

Front 19

Supernova

Back 19

One of the rarely observed nova outbursts in which the maximum intrinsic luminosity may reach 100 million times that of the sun

Front 20

Main Sequence

Back 20

On the Hertzsprung and Russell Graph the main sequence is the diagonal band that runs from the upper left to the lower right of the graph.It contains hot, blue, bright stars in the upper left and cool, red, dim stars in the lower right. Yellow amin sequense stars like the Sun, fall in between