Physical and Earth Science chapter 26

Galaxy

(astronomy) a collection of star systems

High Mass Star

1. Nebula 2. High mass Protostar 3. Main Sequence star 4. Super Red giant 5. Supernova 6. neutron star or black hole

Low Mass Star

1.Nebula 2.Protostar 3.Main-Sequence Star 4.Red Giant 5.White Dwarf 6.Black Dwarf

Planetary nebulas

Glowing shells around dying stars Eventually grow so big and diffuse that they mingle with the interstellar medium, ending the star's life cycle and leaving behind the core (a white dwarf)

H-R diagram

Hertzsprung-Russell diagram, a graph that shows the relationship between a star's surface temperature and absolute magnitude

pulsar

a degenerate neutron star

supernova

a gigantic explosion in which a massive star collapses and throws its outer layers into space., when the core of a massive star collapes violently causing the outer portion of the star to explode

Nebula

a large cloud of dust and gas that can break apart into smaller pieces and form stars

Red giant

a large cool star., The stage in the life cycle of a massive star during which the star increases in size and becomes very bright., stage of star's life when the core contracts, temperatures increase, and outer portion of star expands., a very large star that fuses together larger elements than hydrogen and helium in its core. occurs only to low mass stars

Nuclear Fission

a nuclear reaction in which a massive nucleus splits into smaller nuclei with the simultaneous release of energy

Main Sequence Star

a star that falls into the main sequence category on the H-R diagram; this category contains the majority of stars and runs diagonally from the upper left to the lower right on the H-R diagram

neutron star

a star that has collapsed under gravity to the point that the electrons and protons have smashed together to form neutrons. the small, dense remains of a high-mass star after a supernova. a star that has collapsed under its own gravity

parallax

an apparent change in position of an object with respect to a distant background when veiwed from different locations

Star

any celestial body visible (as a point of light) from the Earth at night

blackhole

core of a super massive star that remains after a supernova; the gravity of the core is so strong that not even light can escape., end of a life cycle for a star ( 3 times more massive than the sun

Giant

late stage in a star's life cycle where its hydrogen is used up, its core contracts, and its outer layers expand and cool

white dwarf

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

Super Giant

life cycle stage of a massive star where the core reaches extremly high temperatures, heavy elements form by fusion, and the star expands

light year

light distance travels in one year (9.5 trillion km)

Super red giant

massive stars become this, gives off outer layer in an implosion called a supernova., enormous, cool, high luminous stars that forms after a huge or giant star has used up the fuel at its core. This occurs only to a High mass star

black dwarf

star that results when a white dwarf stops giving off energy

Absolute Brightness

the brightness a star would have if it were at a standard distance from earth

Apparent Brightness

the brightness of a star as seen from earth

absorption lines

the dark lines in a spectrum where light of particular wavelengths has been absorbed (n)

Protostar

Early form of a star; This stage lies between the collapsing of dust and gas and the beginning of nuclear fusion