Solar System

Planets, moons, dwarf planets and comets

Moons

Mercury Venus Earth Mars

0 0 1 2Gas giants have many (usually small) moons

Solar System

Planets, moons, dwarf planets and comets

Dwarf planets include Pluto and the asteroids

Solar System

Planets, moons, dwarf planets and comets

Comets are ice, rock, and dust in eccentric orbits. They make a tail when they get closer to the Sun.

The Planets (scaled for size)

Mercury

Venus (in infrared)

Do you need a label?

Mars

Jupiter

Saturn

Uranus

Neptune

Pluto (dwarf planet) and its moon, Charon

A comet(notice the two tails)

A comet(notice the two tails)

Towards the Sun

Direction of the comet

Body Diameter (Mm) Distance (AU)

Mercury 4.9 .39

Venus 12 .72

Earth 13 1

Mars 6.8 1.5

Jupiter 140 5.2

Saturn 120 9.5

Uranus 51 19

Neptune 50 30

Pluto 2.2 39

Diameter Distance(Mm) (AU)

Mercury 4.9 .39

Venus 12 .72

Earth 13 1

Mars 6.8 1.5

Jupiter 140 5.2

Saturn 120 9.5

Uranus 51 19

Neptune 50 30

Pluto 2.2 39

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Diameter Distance(Mm) (AU)

Mercury 4.9 .39

Venus 12 .72

Earth 13 1

Mars 6.8 1.5

Jupiter 140 5.2

Saturn 120 9.5

Uranus 51 19

Neptune 50 30

Pluto 2.2 39

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There’s a reason for the seasons

The Earth’s axis is tilted!

Summer in the northern hemisphere

Summer in the southern hemisphere

Other stellar systems?

• As of Jan. 2010, 429 planets have been discovered around other stars.

Stars

• www.astrocappella.com/sun.shtml

• Nuclear fusion of hydrogen to helium releases the energy of a star.

The Herzsprung-Russell Diagram

• Temperature—reversed and logarithmic!

• Luminosity (How much light it makes)—logarithmic and compared to the Sun!

• 102=100 times as bright as the Sun!

• 10-2=1/100th as bright as the Sun!

• 103?

• 10-4?

• Denebola is a star. Its surface temperature is 8900k and it is 17 times as luminous as the Sun

• Mark the position of Denebola on the Herzsprung- Russell diagram.

• Denebola is a star. Its surface temperature is 8900k and it is 17 times as luminous as the Sun

• Denebola is a star. Its surface temperature is 8900k and it is 17 times as luminous as the Sun

Denebola• Denebola is a star. Its surface temperature is 8900k and it is 17 times as luminous as the Sun

…there are kinds of stars?

• Size

• Temperature

• Age

…there are kinds of stars?

• Size: ~1/4 solar mass to 50 solar masses

• Temperature: ~3000-30,000 oC

• Age: brand new to ~10 billion years old.

…there are kinds of stars?

• Size: ~1/4 solar mass to 50 solar masses

• Temperature: ~3000-30,000 oC

• Age: brand new to ~10 billion years old.

The Sun is an average star

…there are kinds of stars?

• A dimmer star, up close, can look brighter than a bright star far enough away.

• A hotter star is brighter than a cooler star (color indicates temperature)

• A larger star is brighter than a smaller star

How bright?

Brighter objects get lower numbers!

Hotter stars look more blue, cooler stars look more red

Color Class Temperature

• Blue O,B,A (over 7500oC)

• White F (6000-7500oC)

• Yellow G (5000-6000oC)

• Orange K (3500-5000oC)

• Red M (less than 3500oC)

Oh, be a fine girl, kiss me!

Color Class Temperature

• Blue O,B,A (over 7500oC)

• White FF (6000-7500oC)

• Yellow G (5000-6000oC)

• Orange K (3500-5000oC)

• Red M (less than 3500oC)

Oh, be a finefine girl, kiss me!

Type ColorSurface

TempSolar

MassLum. Ex.

O Blue >25,000 K 60 1,400,000 Lacertra

BBlue

11,000 -25,000K

18 20,000Rigel

Spica

ABlue

7,500 - 11,000 K

3.2 80Sirius, Vega

FBlue / White

6,000 - 7,500 K

1.7 6Canopus, Procyon

GWhite /Yellow

5,000 - 6,000 K

1.1 1.2Sun,

Capella

KOrange / Red

3,500 - 5,000 K

0.8 0.4Arcturus, Aldebaran

MRed < 3,500 K

0.30.04 Betelgeuse

Antares

A map of your neighborhood

Bright stars are big stars

The Herzsprung-Russel Diagram

The Herzsprung-Russel Diagram

The Herzsprung-Russel Diagram

Small stars

Average stars

Heavy stars

Super-heavy stars

White dwarfs—small and hot

Red giants—large and cool

Binary stars

Neutron star

Black hole (?)

Special stars

• Brown dwarfs—barely big enough to start fusion reactions

• Variable stars—change brightness

Constellations• Groups of visible stars in a recognizable

pattern.Andromeda, the princess

Antlia, the pump

Aquarius, the water bearer

Aquila, the eagle

Aries, the ram

Auriga, the chariot driver

Bootes, the herdsman

Caelum, the chisel

Camelopardalis, the giraffe

Cancer, the crab

Canes Venatici, the hunting dogs

Canis Major, the big dog

Canis Minor, the little dog

Capricorn, the goat

Cassiopeia, the queen

Cepheus, the king

Cetus, the whale

Columba, the dove

Coma Berenices, Berenice's hair

Corona Australis, the southern crown

Corona Borealis, the northern crown

Corvus, the crow

Crater, the cup

Cygnus, the swan

Delphinus, the dolphin

Draco, the dragon

Equuleus, the little horse

Fornax, the furnace

Gemini, the twins

Hercules, the hero

Horologium, the clock

Hydra, the water snake

Lacerta, the lizard

Leo Minor, the little lion

Leo, the lion

Libra, the scales

Lupus, the wolf

Lynx, the lynx

Lyra, the harp

Microscopium, the microscope

Monoceros, the unicorn

Ophiuchus, the sepent holder

Orion, the hunter

Pegasus, the flying horse

Perseus, the Medusa killer

Pisces Austrinus, the southern fish

Pisces, the fish

Puppis, the ship's stern

Pyxis, the ship's compass

Sagitta, the arrow

Sagittarius, the archer

Scorpius, the scorpion

Sculptor, the sculptor

Scutum, the shield

Serpens, the snake

Sextans, the sextant

Taurus, the bull

Telescopium, the telescope

Triangulum, the triangle

Ursa Major, the big bear

Ursa Minor, the little bear

Virgo, the virgin

Vulpecula, the little fox

The Big Dipper (part of Ursa Major)

Casseopia

The Zodiac

Galaxies

• Spiral

• Barred

• Irregular

Other stuff--Nebulas

• Light and dark—a cloud of dust and gas

• A dark nebula blocks the light of stars behind it.

• A light nebula is lit by stars in front of it.

Other stuff--Nebulas

Telescopes

• From “tele-” (far) and “scope” (seeing)

• Any part of the electromagnetic spectrum can be examined.

• Some telescopes must be in orbit (they cannot “see” through the atmosphere)

Refracting Telescopes (use lenses)

A Cassegraine Reflector

Reflecting Telescopes (use mirrors)

Radiotelescopes (use antennas)

Space telescopes (above the atmosphere)

X ray and IR telescopes

• Must be in orbit

Observatories

• Buildings that house telescopes

Griffith Observatory (LA)

Palomar Observatory (CA)

Arecibo (PR)

Mauna Kea (HI)

National Solar Observatory (NM)

Lick (CA)

Caltech

Lowell (AZ)

Very Large Array (NM)