The Sun Astronomy

http://www.luminousnuminous.com/blog/wp-content/uploads/2009/05/sun_tour.jpg

THE SUN

• SOL

• The Sun’s scientific name is Sol (hence

the name “Solar System”)

http://upload.wikimedia.org/wikipedia/commons/thumb/9/9d/Sol_de_Mayo-Bandera_de_Argentina.svg/504px-Sol_de_Mayo-Bandera_de_Argentina.svg.png

http://upload.wikimedia.org/wikipedia/commons/d/d9/Yohkohimage.gif

WHAT IS THE SUN?

• Centre of the Solar System

• A foci for all planets in the Solar System

• A yellow star

• Luminous

• Composed of plasma (an ionized gas) made mostly of hydrogen and helium.

http://www.bnsc.gov.uk/assets/channels/education/ae/solar.gif

OUR STAR’s SIZE

• 1,400,000,000 m diameter

• The Sun could hold 1.3 million Earth’s!

http://www.answersingenesis.org/assets/images/articles/tba/chapter-one/sun-moon-earth.jpg

THE SUN’S MASS

• 750 times the mass of all of the Solar

System’s planets put together

• Between 98% and 99% of the Solar

System’s mass

• 332,830 times the mass of Earth!

• 1.989 x 1030 kg

(1,989,000,000,000,000,000,000,000,000,000kg)

OUR STAR – KEY FACTS

• DENSITY: 1410 kg/m3

– At the Sun’s centre, the density is more than 150 times that of water!

• TEMPERATURE: – Average temperature: Approximately 6270Kelvin

– 6000°C

– This is the same temperature as the Earth’s core!

• ATMOSPHERE: – Made up of immense clouds of glowing gas

– Stretches far into space

– Can only be seen during total solar eclipses

OUR STAR

• Surface temp

= 5500°C

• Core temp =

15 million°C

http://www.rise.org.au/info/Res/sun/image004.jpg

KEY FACTS

• 1) The Sun has no moons or rings.

• 2) The Sun has natural satellites – the planets, dwarf planets, and smaller celestial bodies

• 3) Distance from Earth: 1 AU

• 4) The closest planet is Mercury

• 5) The farthest planet is Neptune

Classifying the Sun

• 1) “Jovian” – made of gases

• 2) “Classical” – can be seen with the

naked eye

– Scientists used to think the Sun was a planet!

GRAVITATIONAL PULL

• Acceleration due to gravity = 274 m/s2

• Compared to Earth’s 9.81 m/s2

http://www.kudzuacres.com/wwow/lessons/weather/oceansurface_files/image003.jpg

OUR STAR – TIMES!

• The core rotates at the same rate but the outer parts of the Sun do not!

• 34 Earth days to rotate at Poles

• 25 Earth days to rotate at Equator

• There is no period of revolution…

http://www.lcsd.gov.hk/CE/Museum/Space/EducationResource/Universe/framed_e/lecture/ch11/imgs/rotation.gif

OUR STAR – TIMES!

• Our Sun is estimated to be approximately

4.5 billion years old.

• It should last another 5 billion years.

• Made initially from a cloud of dust.

• Matter fell inwards, creating heat,

eventually causing nuclear fusion and

producing its own light and energy.

STUDYING THE SUN

• Ancient civilizations studied

the sky and stars

• Many had Sun gods

– Amaterasu (Japan)

– Helios, Apollo (Greek)

– Freyr, Sol (Norse)

– Huitzilopochtli (Aztec)

– Inti (Inca)

– Liza (West African)

– Re/Ra (Egyptian)

STUDYING THE SUN

• In 1609 Galileo built his first telescope

• He saw Sunspots

http://www.telescope1609.com/images/GalileosTelescope.jpg

http://www.norcalblogs.com/watts/images/sunspots_earth_size_big.jpg

SUN MYTHS

• “What if the sun collapses into a black hole?

• Bad Astronomy: If the Sun collapses into a

black hole, the Earth and all the other planets

will get sucked in.

• Good astronomy: If the Sun were to collapse

into a black hole, we would feel no difference in

the gravity as measured at the Earth.

http://www.badastronomy.com/bad/misc/black_hole_sun.html

Sources

• http://z.about.com/d/space/1/5/Y/Q/sun_tour.jpg

• www.answers.com/topic/hertzsprung-russell-diagram

• http://www.answersingenesis.org/assets/images/articles/tba/chapter-one/sun-moon-earth.jpg

• http://www.astro.washington.edu/labs/clearinghouse/labs/Propsun/images/chang_sun2.gif

• http://hometown.aol.com/falconmaster29/downloads/SolarFlare.jpg

• http://www.nasa.gov/images/content/171925main_heliolayers_label_516.jpg

• http://www.space.gc.ca/asc/img/trans_mass_n_weight.jpg

• http://www.geocities.com/ominaga2/amaterasu_classic2.jpg

• http://www.maicar.com/GML/000Free/000Apollo/image/apollo3837.jpg

• http://www.hurstwic.org/history/articles/mythology/myths/pix/freyr.jpg

• http://www.class.uh.edu/courses/engl3396/jtchris2/Huitzilopochtli.jpg

• http://www.unique-southamerica-travel-experience.com/images/inti-copia.jpg

• http://www.telescope1609.com/images/GalileosTelescope.jpg

• http://astronomy.neatherd.org/Swedish%20sunspots1.jpg

• http://abyss.uoregon.edu/~js/images/pioneer6.jpg

• http://www.deutsches-museum.de/uploads/pics/helioskl_05.jpg

• http://library01.gsfc.nasa.gov/gdprojs/images/smmrepair.jpg

• http://www.sflorg.com/missionnews/ulysses/images/immn081707_01_01.jpg

• http://msnbcmedia3.msn.com/j/msnbc/Components/Photos/051129/051129_soho_hmed2p.h2.jpg

• http://library01.gsfc.nasa.gov/gdprojs/images/trace.jpg

• http://en.wikipedia.org/wiki/Sun

• Information from “Universe: the definitive visual guide” senior editor: Peter Frances