The Big Bang Theory and Stellar Evolution

Big Bang

Origin event of the universe, 13.7 billion years ago.

Big Bang Theory

All matter and energy originated from a small area.

Cosmic Background Radiation

Long-wave microwave radiation from the Big Bang.

Red Shift

Wavelength stretching indicating universe expansion.

Elliptical Galaxies

Largest galaxies, older stars, less gas and dust.

Spiral Galaxies

Galaxies with winding arms and bright central bulges.

Irregular Galaxies

Galaxies lacking defined shape and structure.

Hydrogen

First atom formed after the Big Bang.

Helium

Second atom formed after the Big Bang.

Dark Matter

Comprises 27% of the universe, holds galaxies together.

Dark Energy

Accounts for 68% of universe, accelerates expansion.

Hertzsprung-Russel Diagram

Classifies stars by luminosity, temperature, and color.

Luminosity

Brightness of a star, plotted on HR diagram.

Spectral Type

Classification based on star's color and temperature.

Absolute Magnitude

Intrinsic brightness of a star at standard distance.

Cosmic Radiation

Energy from the Big Bang, expanding with matter.

Galactic Composition

Elements found in stars inferred from spectral analysis.

Universe Expansion

Continuous growth of the universe over time.

Gravitational Effects

Dark matter and energy influence through gravity.

Star Characteristics

Stars differ in mass, size, temperature, and color.

Stellar Evolution

Changes in stars over time, illustrated by HR diagram.

Milky Way Galaxy

Example of a spiral galaxy containing older stars.

Star Mass

Greater mass increases gravity, heat, and density.

Star Energy

Core pressure converts matter into energy.

Star Stability

Fusion energy counters gravitational collapse.

Fusion vs Gravity

Fusion greater leads to expansion; less leads to contraction.

Thermonuclear Fusion

Occurs faster in massive stars, consuming fuel quickly.

Star Temperature

Blue stars are hottest; red stars are coolest.

Hertzsprung-Russell Diagram

Plots stars by luminosity and temperature.

Main Sequence Stars

90% of stars are stable, middle-aged stars.

Red Giants

Large, cool, bright stars; 1% of stars.

White Dwarfs

Remnants of stars, dense, hot, made of carbon.

Nebula

Cloud of gas and dust, star formation birthplace.

Protostar

Heating gas in nebula initiates nuclear fusion.

Red Giant Phase

Star expands and cools as hydrogen depletes.

Planetary Nebula

Gas cloud forms around dying sun-like stars.

Black Dwarf

Cool, dark remnant of a white dwarf.

Red Super Giants

Massive stars evolve into red super giants.

Supernova

Massive explosion from collapsing supergiant core.

Neutron Star

Dense remnant, mass of sun compressed to city size.

Pulsars

Rapidly rotating neutron stars emitting radio pulses.

Supernova Shockwave

Explosion blows away outer layers of a star.

Fusion Stops

Carbon fusion halts, leading to core collapse.

Iron Formation

Massive stars create iron before fusion ceases.

Stellar Remnants

Objects left after a star's life cycle ends.

Black Hole

Forms from a core over 9 solar masses.

Core

Dense center of the Sun, energy generation site.

Radiative Zone

Layer where energy is transferred by radiation.

Convective Zone

Region where gas circulates in convection currents.

Photosphere

Visible surface of the Sun, emits light.

Chromosphere

Middle layer, emits reddish light during eclipses.

Corona

Outer layer, visible as a halo during eclipses.

Sunspots

Cooler gas areas, appear as dark spots.

Prominences

Looping gas eruptions near sunspots.

Solar Flares

Explosive gas bursts releasing massive energy.

Solar Winds

Charged particles ejected from the corona.

Auroras

Northern and southern lights from solar particles.

Magnetic Storms

Temporary disturbances in Earth's magnetosphere.

Year

Time for a planet to orbit the Sun.

Revolution

Body orbiting another body in space.

Period of Revolution

Time to complete one orbit around the Sun.

Prograde Rotation

Counterclockwise spin direction of planets.

Retrograde Rotation

Clockwise spin direction of planets.

Geocentric Model

Earth-centered theory of the solar system.

Heliocentric Model

Sun-centered theory of the solar system.

Mercury

Planet with extreme temperature fluctuations.

Venus

Hottest planet, dense carbon dioxide atmosphere.

Mars

Cold planet with ice caps and thin atmosphere.

Mars Poles

Thin ice layers at both poles.

Olympus Mons

Largest volcano, 600 km diameter, 24 km high.

Phobos

One of Mars' two small moons.

Deimos

Second small moon of Mars.

Jupiter

Largest planet in the solar system.

Jupiter's Radius

Approximately 11 times Earth's radius.

Jupiter's Moons

Has 95 known moons.

Jupiter's Composition

Mostly hydrogen and helium with dense core.

Liquid Metallic Hydrogen

Creates Jupiter's huge magnetic field.

Great Red Spot

Hurricane-like storm on Jupiter.

Saturn

Second largest planet, characterized by rings.

Saturn's Radius

About nine times Earth's radius.

Saturn's Moons

Has 275 moons, including 128 small moons.

Saturn's Density

Least dense planet at 0.69 g/cm³.

Saturn's Diameter

250,000 km, greater than Earth-Moon distance.

Uranus

Radius about four times that of Earth.

Uranus' Moons

Has 28 known moons.

Uranus' Composition

More ice than gas compared to Jupiter.

Uranus' Axis Tilt

Tilted 98 degrees from its orbit.

Neptune

Radius about four times that of Earth.

Neptune's Moons

Has 16 confirmed moons.

Neptune's Atmosphere

Mostly hydrogen, helium, and methane.

Neptune's Winds

Fastest winds in the solar system, 1,000 km/hr.

Great Dark Spot

Storm on Neptune, size of Earth.

Tidal Locking

Moon's gravity keeps one face towards Earth.

Giant Impact Theory

Moon formed from Earth's collision with a Mars-sized body.

Ganymede

Largest moon in the solar system, larger than Mercury.

Europa

Jupiter's moon with a subsurface ocean.

Io

Most volcanically active body in the solar system.

Titan

Saturn's largest moon with a dense atmosphere.

Enceladus

Brightest moon, features geysers and ice water plumes.

Mimas

Saturn's moon nicknamed 'The Death Star'.