Vocabulary#10 Stars

Star:A large ,hot ball of gases, which is held together by gravity and gives off its own light.
S:Stars are far,far away from Earth.

Parallax:The apparent shift in an object`s location when viewed from two positions.
S:The closer a star is,t he greater the shift of a parallax is.
 
Light-Year:The distance light travels in a year.
S:Astronomers use a unit called light-year(ly).

Constellation:A number of star that appears to form a pattern.
S:My favorite constellation is the Lyra.

Magnitude:The brightness of a star.
S:The Magnitude is use in two ways in absolute and apparent magnitude.

Nebula:A cloud of gas and dust in space.
S:As time goes,the gravity cause nebula to contract.

Supernova:A star that explodes.
S:When a star collide or explode is called supernova.

Black hole:An object whose gravity is so strong that light cannot escape it.
S:When a star collapse it becomes a black hole.