The expanding universe

Question 1

what are stars?

Answer 1

stars are globes of helium that produce their own heat and light through nuclear reactions

Question 2

what is the life cycle of the sun?

Answer 2

they begin as protostars, which form condensing gases called nebulae, when the protostar reaches a certain density and temperature, nuclear reactions begin, releasing huge amounts of energy. At this point, the star is known as a man star sequence is the longest life cycle in the stellar life cycle.

Question 3

what happens after the main sequence life cycle?

Answer 3

after billions of years, the star begins to run out of hydrogen fuel and it may become and giant, in time the red giant either collapses, exploding into a supernova and leaving behind a neutron star or losing mass and becoming a white dwarf.

Question 4

what does galaxies consist of?

Answer 4

between one million and one trillion stars, along with clouds of gas and dust which are held together by gravity.

Question 5

what are the 2 largest galaxies in the local group?

Answer 5

the milky way and the andromeda galaxy

Question 6

what does the universe mostly consist of?

Answer 6

empty space with galaxies scattered throughout

Question 7

what are other bodies of the universe?

Answer 7

• brown dwarfs
• pulsars
• quasars

Question 8

what are brown dwarfs?

Answer 8

objects that are less massive than a star but more massive than a planet

Question 9

what are pulsars?

Answer 9

rotating neutron stars that emit pulses of energy at regular intervals

Question 10

what are quasars?

Answer 10

distant starlike objects that emit more energy than a hundred galaxies