Flashcards in The expanding universe Deck (10)
what are stars?
stars are globes of helium that produce their own heat and light through nuclear reactions
what is the life cycle of the sun?
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.
what happens after the main sequence life cycle?
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.
what does galaxies consist of?
between one million and one trillion stars, along with clouds of gas and dust which are held together by gravity.
what are the 2 largest galaxies in the local group?
the milky way and the andromeda galaxy
what does the universe mostly consist of?
empty space with galaxies scattered throughout
what are other bodies of the universe?
- brown dwarfs
what are brown dwarfs?
objects that are less massive than a star but more massive than a planet
what are pulsars?
rotating neutron stars that emit pulses of energy at regular intervals