Unit 6 Universe Vocab

Question 1

Apparent magnitude

Answer 1

The brightness of a star as seen from earth

Question 2

Big Bang theory

Answer 2

The theory that all matter and energy in the universe was compressed into an extremely small volume that 13-15 billion years ago exploded and began expanding in all directions

Question 3

Cosmic microwave background(CMB)

Answer 3

The electromagnetic radiation left over from the formation of the universe

Question 4

Doppler effect

Answer 4

An observed change in frequency or wavelength when the source is moving with respect to the observer

Question 5

Electromagnetic spectrum

Answer 5

All of the different wavelengths and frequencies of electromagnetic radiation, from radio waves to gamma rays

Question 6

Galaxy

Answer 6

A collection of stars, dust, and gas bound together by gravity

Question 7

H-R diagram (Hertzsprung- Russell diagram)

Answer 7

A graph that shows the relationship between a stars surface temperature and absolute magnitude

Question 8

Light year

Answer 8

The distance that light travels in one year; about 9.46 trillion km

Question 9

Luminosity

Answer 9

The actual brightness of an object such as a star

Question 10

Main sequence

Answer 10

The region on the H-R diagram where stars spend most of their lives; it has a diagonal pattern

Question 11

Nebula

Answer 11

A large cloud of dust and gas in interstellar space; stars are born here

Question 12

Planet

Answer 12

A relatively large spherical body that orbits a star

Question 13

Neutron star

Answer 13

The core of a supernova that has collapsed under gravity to the point that the electrons and protons have smashed together to form neutrons

Question 14

Pulsar

Answer 14

A highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation

Question 15

Red shift

Answer 15

A phenomenon which occurs when a star of galaxy is moving away from the earth and its wavelengths emitted are stretched out due to the Doppler effect

Question 16

Revolution

Answer 16

The motion of a body that travels around another body in space

Question 17

Rotation

Answer 17

The spin of a body on its axis

Question 18

Solar system

Answer 18

A collection of large and small bodies that orbit our central star, the sun

Question 19

Spectroscope

Answer 19

A tool used to collect light from stars and separate the colors in the light

Question 20

Star

Answer 20

A large celestial body that is composed of gas and emits light; the sun is a typical star

Question 21

Supernova

Answer 21

A gigantic explosion in which a massive star collapses and throws its outer layers into space, but its core remains

Question 22

Universe

Answer 22

Space and all the matter and energy in it

Question 23

Wave length

Answer 23

The distance between two adjacent crests or troughs of a wave

Question 24

White dwarf

Answer 24

The hot, dense , dim core of matter remains from the collapse of a lowmass star

Question 25

Spiral galaxy

Answer 25

A galaxy shaped like a pin wheel, with a center bulge and spiral arms extending outwards

Question 26

Elliptical Galaxy

Answer 26

A spherical or elongated Galaxy with a bright center and very little dust and gas

Question 27

Irregular Galaxy

Answer 27

A Galaxy with an irregular shape and doesn’t fit in any oh her category

Question 28

Absolute magnitude

Answer 28

A brightness scale used to measure how bright a star would be if it were seen from a standard distance