Transcript Sun Powerpoint

The Sun
Miss Butler
Astronomy 12
March 22, 2010
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/d/d9/Yohkohimage.gif
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
WHAT IS THE SUN?
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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
• The obliquity (or axial tilt) of the Sun is
7.25°
http://en.wikipedia.org/wiki/File:AxialTiltObliquity.png
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
GRAVITATIONAL PULL
• Fg=mg
• Earth
• Fg = 70 x 9.81
= 686.7 N
Sun
Fg = 70 x 274
= 19,180 N
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.
BRIGHTNESS
• −26.74 visual magnitude
• Brightest object in sky from Earth
STUDYING THE SUN
• Ancient civilizations studied
the sky and stars
• Many had Sun gods
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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
STUDYING THE SUN
• 1960’s
• PIONEER 5 to 9
• Orbited the sun
– Solar wind
– Solar flares
– Magnetic fields
http://abyss.uoregon.edu/~js/images/pioneer6.jpg
STUDYING THE SUN
• 1974 & 1976
• HELIOS
• High-velocity passes
close to Sun’s
surface
– Solar wind
– Magnetic field
http://thelongestlistofthelongeststuffatthelongestdomainnameatlonglast.com/images4/helios.JPG
STUDYING THE SUN
• 1980
• SOLAR MAXIMUM
MISSION
– X-rays
– Gamma rays
– Ultraviolet radiation
– From flares and
sunspots
http://library01.gsfc.nasa.gov/gdprojs/images/smmrepair.jpg
STUDYING THE SUN
• 1990
• ULYSSES
• 1st polar orbiting
probe
• Still in operation
• “Fly by”
http://science.nasa.gov/headlines/y2008/images/northpole/Ulysses_spacecraft.jpg
STUDYING THE SUN
• 1991
• YOHKOH
• Earth-orbiting
satellite observed
high-energy
radiation
http://heasarc.gsfc.nasa.gov/Images/objects/heapow/solar_system/yohkoh_solar_cycle.jpg
STUDYING THE SUN
• 1995
• SOHO
• Studies the Sun’s
interior and
surface
http://msnbcmedia3.msn.com/j/msnbc/Components/Photos/051129/051129_soho_hmed2p.h2.jpg
STUDYING THE SUN
• 1998
• TRACE
• Studies the Corona
http://library01.gsfc.nasa.gov/gdprojs/images/trace.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. “ (Note the
quotations as I have copied this!!!)
http://www.badastronomy.com/bad/misc/black_hole_sun.html
Sources
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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