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Flashcards in The Universe Deck (12):
1

what are exoplanets

planets that do not orbit our sun

2

what is dark energy

a mysterious force of negative gravity

3

what is dark matter

matter that is invisible to astronomers but can be detected by its gravitational effects

4

name two factors of the drake equation

number of stars in our Galaxy

&

fraction of stars with planetary systems

5

how are stars formed

the collapse of huge clouds of gas and dust

6

what is a main sequence star

where the star spends most of its life

7

what happens when a main sequence star star collapses

it becomes a supergiant or a red giant

8

what is at the centre of a supernova remnant

neutron star or a black hole

9

what is at the centre of a supernova remnant

neutron star or a black hole

10

what is the period luminosity law

the period luminosity law is that the length of a cepheid variables pulsation determines how bright the star is

11

what is a parsec

the distance at which a star would have an angle of one arcsec

12

what is heliocentric Parallax

calculates the distance to a nearby star by taking two different viewpoints (six months apart) and seeing how much the star moves