ORIGIN OF THE UNIVERSE UNIT 2 Big Bang

Green: DARK ENERGY No one knows what dark energy is. Some astronomers theorized that a substance called dark energy produces pressure like antigravity to cause the universe to expand Red: NORMAL MATTER Everything that emits enough radiation for astronomers to detect falls under the category of normal matter. This includes neutron stars, distant galaxies, & quasars Purple: DARK MATTER Dark matter is partially composed of objects that are difficult to detect, such as black holes, brown dwarfs, and intergalactic dust. It may also include particles that scientists have not yet discovered

There are many theories on the origin of the Universe There are many theories on the origin of the Universe. Some are supported more than others STEADY STATE THEORY: - The universe was always here. New matter is continuously created. Even though the mass increases, the stars do not change their position in relation to each other. * Later research has shown that the universe is changing and this theory has lost support.

BIG BANG THEORY: - Suggest that the universe originated from a small amount of matter (hydrogen) that expanded rapidly (exploded). All planets, stars, comets, etc are the debris that is still drifting outward from this explosion. * There are many flaws to this theory, but scientifically it is the most supported answer. Inflation Theory (IUT) is gaining ground. * The Universe is estimated to be 13.7 Billion Years

Order Within the Universe Universe - The total amount of matter and energy in existence (It encompasses everything) Super Cluster - A collection of star clusters found in the universe Star Cluster - A collection of star groups found within the super cluster

Star Group - Collections of similar galaxies found within a cluster Star Group - Collections of similar galaxies found within a cluster. Our galaxy is found in the “Local Group” which contains about 29 other galaxies Galaxy - A collection of similar stars found within a star group. Our galaxy is called the Milky Way and contains about 200 Billion Stars. - There may be about 100 Billion Galaxies in the Universe.

Star System - A small group of planets and moons that orbit 1-4 stars Star System - A small group of planets and moons that orbit 1-4 stars. Our system is called the “Solar System” and contains 1 Star (Sun), 8 Planets (Earth is one of them), and about 59 Moons. Star - A large ball of gas releasing energy and matter due to the fusion of hydrogen & helium atoms (Sun).

UNIT 2 – 2.2 LifeCycle of a Star Lifecycle of a Star (Size of our Sun) Nebula-Star-Red Giant-Nova-White Dwarf-Black Dwarf Lifecycle of a Star (100x that of our Sun) Blackhole Nebula-Giant-Super Giant-Supernova Neutron Star

Nebula - A large cloud of dust and gases that are pulled together by gravity. The stuff stars are made from (beginning of all stars) Red Giant - A star that has turned all its hydrogen fuel into helium. The outside expands and cools as the inside condenses and forms carbon from helium (beginning of the end) White Dwarf - When all of the helium fuel of the Red Giant has been used. The outer layers explode off into space just leaving the white hot core (very small nearing the end of life)

Supernova - Massive stars collapse more violently after the Red/Super Giant Phase. This causes the whole star to explode and nothing remains but neutrons or a blackhole. Debris from a Nova or a Supernova can become a Nebula and start the process over. Blackhole - A celestial object with such extreme gravity that it attracts everything near it, even light (End result of massive stars)

A Star’s Brightness is Determined by 3 Things 1. Size – 13,000 km in Diameter to 300,000,000 km - Larger stars burn hotter, brighter, and shorter due to the rapid burning of its fuel. 2. Distance – The further away the dimmer they appear 3. Temperature – Hotter stars are brighter Red – Orange – Yellow – White – Blue Cooler 2,000,000 Degrees C  Hotter 20,000,000 Degrees C

Constellation - A group of stars that appear close together and form patterns or pictures (Orion, Ursa Major, Etc.) Light Year - Unit of measuring distance – How far light can travel in a year (6 Million Miles). Closest Star 4.2 / Andromeda Galaxy 2.2 Million