Ch. 22 Stars and Galaxies

Spectroscope

A device that uses a prism or diffraction grating to separate light into its color components is called a ________. ________ spreads light in different wavelengths.

Supernova

A gigantic explosion in which a massive star collapses and throws its outer layers into space is a _______. A _______ is an enormous explosion that destroy's a star.

galaxy

A huge group of single stars, star systems, star clusters, dust, and gas bound together by gravity is a _______. A ______ is a huge collection of stars.

Nebula

A large cloud of dust and gas in space is a ______. A cloud consisting of gas and dust is a _______.

white dwarf

A small, hot, dim star that is the leftover center of an old star is a _________. A ________ is a hot, dense slowly cooling sphere of carbon.

neutron star

A star that has collapsed under its own gravity is a ________. A _______ is a dense core of neutrons that remains after a supernova.

black hole

An object in space whose gravity is so strong not even light can escape is a _______. A _______ is an object that has gravity so great that light cannot escape it.

Big Bang Theory

Cosmological model that explains the sudden development of the universe through expansion from a hot, dense state is the ________. ________ says that the universe began from one point billions of years ago and has been expanding ever since.

Photosphere

The inner layer of the sun's atmosphere is the ______. The _____ is the apparent surface of a star.

corona

The outer layer of the sun's atmosphere is the _____. The _____ is the wide, outermost layer of a star's atmosphere.

convection zone

The outermost layer of the sun's interior is the ________. The ______ is a place where hot gas moves up toward the surface and cooler gas moves toward the interior.

Chromosphere

______ is a gaseous layer of the sun's atmosphere (extending from the photosphere to the corona) that is visible during a total eclipse of the sun. The _____ is the orange-red layer above the photosphere.

nuclear fusion

______ is a nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy. _______ is a process that occurs when the nuclei of several atoms combine to form one large nucleus.

apparent magnitude

______ is the brightness of a star as seen from Earth. The ________ of an object is a measure of how bright it appears from Earth.

light-year

______ is the distance light travels in one year. _______ is how fast light can go and travel in a year.

star

_______ is a fixed luminous point in the night sky that is a large, remote incandescent body like the sun. A ______ is a large ball of gas that is held together by gravity and has a core so hot that is creates nuclear fusion.

astronomical unit

_______ is a unit of length used for distances within the solar system. An _____ is the average distance between the Earth and the Sun.

Radiative zone

_______ is a very dense region of the sun in which the atoms are so closely packed that light can take millions of years to pass through. The ______ is a shell of cooler hydrogen above a star's core.

dark matter

_______ is matter that does not give off electromagnetic radiation but is quite abundant in the universe. Matter that emits no light at any wavelength is ________.

Luminosity

_______ is the true brightness of an object. ________ is how bright something actually is.

Doppler shift

________ is the moving from one wavelength to another. _______ is the shift to a different wavelength.

Hertzsprung-Russell diagram

___________ is a graph relating the surface temperatures and absolute brightness of stars. ___________ is a graph that plots luminosity v. temperature of a star.