Solar Systems are formed
Are needed for galaxies
Repeats
High to Low Frequency
Both agreed on the heliocentric system but were afraid of the Church
Science throughout the ages and eras
From these come comets (rocky materials, ice, gas), upon reaching Jupiter, some either get captured by Jupiter's gravitational force or enter the inner solar system in which the Sun's radiation creates a tail around the comet due to the radiation releasing gas and particles into the comet which are then pushed away by the Sun's wind, the white part of a tail is the sunlight reflecting off the particles and the blue part is the gas being ionized, some comets visit the Sun once and some are orbiting it (periodic comets)
Both contributions helped Hubble with his discovery
Both agreed of the Geocentric Theory
Both require protostars
Galaxies are made of dark matter clumping together which attract dust and gas (formation of solar systems + nebulae), this all added up (stars, planets, solar systems, nebulae, etc.) forms a galaxy

Astronomy

Study of the universe beyond the earth.

Solar Systems

Stars

Formation

Hydrogen Gas + Dust (Nebulae)

Protostar

At 1x10^7°C, Nuclear Fusion occurs

Nuclear Fusion = Fusion of 2 or more atomic Nuclei

H -> He (It goes on Depending on the mass of the star)

Forces Balance (Gravity Inward, Fusion Outward)

Balance = Stable Star

Types of Stars

White Dwarf

Dense, hot, small

Main Sequence

90% of all stars

Giants

Cool, large, bright

Supergiants

Cooler, extremely large, extremely bright

Life Cycle (After protostar and star formation)

Ms = Solar Mass (Relative to Sun's Mass)

<1Ms

Red Dwarf

White Dwarf

Heats up due to nuclear fusion (becomes white dwarf)

Black Dwarf (Cools Down)

H -> He

(1x10^12 years of lifetime, Long life )

1-8Ms

Yellow Star

(1x10^10 years of lifetime, Average life)

Red Giant

Planetary Nebula (Outer layers of star expel into space)

Core compresses

White Dwarf

Black Dwarf

Chemical Composition: To C

>8Ms

Blue Giant

Chemical Composition: To Fe

(1x10^9 years of lifetime, Short life)

Red Supergiant

>10Ms

Supernova (No more nuclear fusion, Gravity collapses core, chemical composition: To U)

Neutron Star (Dense, small, rotates incredibly fast)

(If >20Ms)

Black Hole (Gravity pulls in on itself, so dense that light can't even escape its gravitational pull)

Stars radiate the entire electromagnetic (EM) spectrum which tells us about them

Gamma rays

X-rays

Ultraviolets

Visible

Infrared

Microwave

Radio

Our Sun

Photosphere (Surface layer of the Sun)

Sunspots (Charged Particles disturb the photosphere and appear darker due to the difference in temperature and create strong magnetic fields)

Solar Flares (Ejections of intense steam of charged particles into space, these steams are known as "Solar Wind", upon the interaction of solar winds and our Earth we get auroras which are just the charged particles passing through our magnetic fields, generating electric current that flows to our poles and charges gases, creating light

Planets

Formation

Protostar (Gravitational Center)

Swirling dust and Hydrogen gas

Planetesimals

Planets

Planets in our solar system

Terrestrial

Mercury

No atmosphere, From Extremely hot to freezing cold, smallest planet

Venus

Acid Rain (Sulfuric Acid), Dense atmosphere trapping heat, Hottest planet, Earth's sister, Similar to earth in size and composition

Earth

Only discovery of life, water in 3 forms, perfect atmosphere, temperature, etc.

Mars

Red Planet due to high concentration of Fe in its rocks, 2 polar ice caps, thin atmosphere

Jovian (Gaseous)

Jupiter

Gas Giant, Largest planet, Massive Red Storm

Saturn

Main composition of atmosphere: H & He, Rings

Uranus

Rotates on its side, rings, methane gas atmosphere

Neptune

Furthest planet from sun, similar to Uranus

Comets, Asteroids, Meteoroids, Moons

Moons

Satelites (Celestial object orbiting another celestial object)

Phases of the moon

Moon phases are created by the reflection of sunlight on its surface (always half-luminated, what we see is based on where the moon is relative to Earth

New Moon

Waxing Crescent

First Quarter

Waxing Gibbous

Full Moon

Waning Gibbous

Third Quarter

Waning Crescent

Eclipses

When a celestial object moves directly in front of another celestial object

Penumbra and umbra are the inner and outer shadow of the Earth

Solar Eclipse

Can only occur during a new moon, the Moon's shadow falls on the Earth's surface and is in between the Sun and the Earth, on average only twice a year however, due to the shadow's size being smaller, you often have to be in a remote or specific place to see the solar eclipse, it is not safe to look at the solar eclipse with just your eyes as the radiation can damage them

Lunar Eclipse

Can only occur during a full moon, the Earth passes in between the Sun and the moon and can result in a partial lunar eclipse (penumbra shadow) or a total lunar eclipse (umbra shadow), the moon's orbit is tilting resulting in only 2 lunar eclipses on average per year, the moon can appear reddish during a lunar eclipse and is completely safe to watch

Tides

Tides occur due to the gravitational difference of the Moon and the Earth

Meteors, Meteoroids, Meteorites

Meteoroids (Pieces of rocks moving through space, thought to be broken parts of asteroids and planets)

Meteors (Meteoroids that enter the Earth's atmosphere and begin to burn up due to atmospheric friction)

Meteor Showers are what people also call "Shooting Stars", though they aren't stars and are in fact meteors, when the Earth passes through an area filled with these meteors, a meteor shower occurs

Meteorites are the surviving meteors (ones that reached the ground without fully burning up)

Asteroids

Asteroids are thought to be debris left over from the formation of the Solar System, non-spherical, small, some have moons

The Asteroid Belt is a band of asteroids that orbit the sun in between Mars and Jupiter

Comets

Trans-Neptunian Objects (Objects beyond the orbit of Neptune

Oort Cloud (Spherical, Icy cloud of small debris)

Kuiper Belt (Disk shaped group of millions of small objects orbiting the Sun and are thought to be from the formation of the Solar System

Units and Measure

AU

1 AU = 1.5x10^8 km (Distance between our Earth and Sun)

Used for distances within our Solar System

Light Years

approx. 9.46x10^12 km (Distance light travels in a Earth year)

Used for interstellar distances

Galaxies

Types of Galaxies

Spiral

Barred-Spiral

Lenticular

Irregular

Elliptical

Formation of Galaxies

Hydrogen Gas + Dust (Nebulae)

Protostar

Star

Swirl of Dust (Protoplanetary Disk)

Planetesimals

Planets

Beyond the Solar System

Exoplanets (Planets beyond our solar system)

History of Astronomy

Antiquity (Time, Date, Navigation)

Egyptians (4200 BCE, 365 day calendar) (Before Common Era)

Chinese (2000 BCE, Observatories)

Babylonians (1000 BCE, Predicts Lunar Eclipses)

Greeks (150 BCE, Star map magnitude 1-6, reject supernatural)

Miletus (585 BCE, Predicted Solar Eclipse)

Pythagoras (540 BCE, Triangulation, quantified abstract ideas, c² = a² + b², Parallax = change in apparent position relative to a distant background when observing 2 different points)

Aristotle (322 BCE, Geocentric Theory, Crystals hold stars)

Ptolemy (140 BCE, Math Models of epicycles to describe the retrograde motion of mars)

Dark Ages (476-1500, No major science except Astronomy for Easter)

Renaissance (1300-1400, return of the arts and international trade)

The Press (1400, information available to the public)

Scientific Revolution (1500, Copernicus - Newton)

Copernicus (1543, Heliocentric Solar System, Afraid of the Church

Tycho (1588, Observations and Supernova)

Bacon (Early 1600's, Scientific Method)

Lippershey (1608, Telescope)

Kepler (1609, assistant to Tycho, 3 laws of planetary motion

3. The longer a planet's orbital radius, the slower it orbits

2. Equal area in equal time (Planets move faster near the Sun)

1. All planetary motion is elliptical

Galileo (1610, Jupiter's moons orbit Jupiter, objects can orbit something other than Earth, proved the geocentric theory wrong, put on house arrest by the Church)

Newton (1665, Explained Kepler's laws with the concept of gravity, type of orbit depends on the mass and speed of the object, gravitational attraction and speed opposes it

Elliptical: Small mass or low speed

Circular: Speed doesn't create eccentricity (perfect conditions)

Hyperbolic: Great speed or distance

Spiral: Low mass or speed

Halley (1682, Predicted that the same comet returns, Halley's comet)

Bradley (1729, Speed of light = 3x10^5 km/s, "c", used a star parallax)

Einstein (1905, Special and general theory of relativity, gravitational lensing, predicted black holes 1916, proven 1971)

Gravitational lensing: Magnifying light through distorted space and galaxies

General Theory of Relativity: Gravity distorts space and time.

Special Theory of Relativity: Time dilation, All movement is relative and speed of light has a limit, time slows down as we speed up

Henrietta Leavitt (1908, Measures distances according to the rhythm of the Cepheid supergiant signal)

Slipher (1919, The gap in the spectrum, red light = receding, blue light = approaching)

Hubble (1929, Expansion of the universe, observed red light)