| A | B |
|---|
| This is a measure of the amount of a star's light received by Earth | apparent magnitude |
| This is higher for close stars | parallax |
| This happens when a nebula contracts and its temperature increases to 10 million K | fusion begins |
| This has an event horizon | black hole |
| This forms when the sun fuses hydrogen | helium |
| describes giant stars | cool, bright stars |
| loops of matter flowing from the sun | prominences |
| groups of galaxies are called | clusters |
| galaxies shaped like footballs are called this | elliptical |
| Scientists study this to determine shifts in wavelengths of light | spectrum |
| This is a measure of the amount of light a star gives off | absolute magnitude |
| The universe began with an enormous explosion 13.7 billion years ago | big bang theory |
| This is a layer of the Sun's atmosphere above the photosphere | chromosphere |
| patterns of stars in the night sky | constellation |
| largest layer of the Sun's atmosphere | corona |
| large group of stars, gas, and dust held together by gravity | galaxy |
| late stage in the life of a low-mass main sequence star | giant |
| distance that light travels in one year | light year |
| large cloud of gas and dust that breaks into smaller pieces to form a star | nebula |
| collapsed core of a supernova that shrinks in diameter - it contains only neutrons | neutron star |
