Transcript Sun - TeacherWeb

Star Life Cycles
and
Nuclear Science
2013 V2
31 Slides,
I hope you like it.
(1 & 2) Kilometers
One kilometer = 1000 meters
Kilometers are used
to measure
distances on Earth.
www.bnsc.gov.uk/.../ae/earth_splash.jpg
(3 & 4) Astronomical Units
One Au is the average distance between the Earth and
the Sun. The solar system is measured in Aus.
www.floridastars.org/icons/solsysna.gif
(5 & 6) Light Years
A light year is the distance light travels in one year.
The Milky Way is 100,000 Light Years across
The Milky Way is measured in light years.
http://apod.nasa.gov/apod/ap960213.html
(7&8) Parsecs
Parsec is short
for parallax
second.
Distances
Between
galaxies
are measured
in parsecs.
http://www.smv.org/hastings/student2.htm
(10) Star Life Cycles
This theory explains why the stars we see have vastly different appearances.
Blue = young stars, yellow = middle aged stars, red = old stars.
(11,12 &13) Hertzprung – Russel (HR) diagram
The HR
diagram
plots star
absolute
brightness
on the
y-axis
and star surface temperature on the x-axis
(14 - 19) The Main Sequence
• Most stars including the Sun are in their mid-life.
• Most stars including the Sun are plotted in the
main sequence of the HR diagram.
Main Sequence
Stars
The Sun
SuperGiants
Giants
White
Dwarfs
(20 & 21) Apparent Brightness
The apparent brightness is what a star looks like from Earth
http://hou.lbl.gov/~vhoette/Explorations/PleiadesStars/index.html
It depends on a star’s: Temperature, size, distance from Earth
(22 - 24) Mass and Life Cycle
The life cycle a star will follow depends on its mass.
.
Super-giant stars such as Polaris end their lives in supernova explosions.
Small to medium stars like the Sun end their lives as white dwarfs.
(25 – 32) Life Cycle of the Sun
The
Sun
•
•
•
•
The sun is:
a medium sized star
92% H and 8% He
yellow and middle aged
5 billion years old
When the H runs out,
the sun swells up to become
a Red Giant as large as
the orbit of Mars.
Yikes!
White
Dwarf
The sun will die in 5 billion years.
the sun will end its life
as a white dwarf, a dead star.
Red
Giant
With
Oxygen &
Carbon
Core
31. (again)
A star is born when gravity crushes the
nebula until fusion starts in its core.
32. Life Cycle of a star
The life cycle of a star depends on its mass
At the end of the life of a super giant star, it explodes in the largest bang the
universe has to offer.
http://imagine.gsfc.nasa.gov/docs/science/know_l1/supernovae.html
33. Hertzprung – Russel (HR) Diagram
The HR
diagram
plots star
absolute
brightness
on the
y-axis
and star surface temperature on the x-axis
(34 & 35) Fusion
H + H  He + energy
Fusion powers the stars
36. Radiation From the Sun
All stars radiate: Heat, (IR), Visible light (VIS) and
Ultraviolet (UV) energy.
Solar energy travels to the Earth in waves.
Fast moving particles from the sun are
called the solar wind. They
push comet tails out
and damage
satellites.
http://www.solarviews.com/eng/comet.htm
37. What comes from Stars?
Light and heat waves and
solar wind particles
Solar
flares
and the
solar
wind
The Earth’s
magnetic field
Protects
the Earth
from the
solar wind.
http://www.chabotspace.org/vsc/solar/spaceweather/curriculum/107_Magnetic%20Configuration.pdf
38. Spectra Lines
Each element makes a unique emission spectrum
Spectral lines tell us which elements are in a star.
Continuous Spectrum
Emission Spectrum
Absorption Spectrum
http://csep10.phys.utk.edu/astr162/lect/light/absorption.html
39. Gravity and Fusion are
Balanced
During the main sequence, there is a balance between
the nuclear fusion that wants to expand a star and
gravity that wants to crush it.
40. Star Color Shows Temperature
• Blue stars are young and hot
• Yellow stars are middle aged and medium
• Red stars are old and cooler
The
Sun
41. First Matter After the Big Bang
The first element to form after the big bang was Hydrogen
The Hindenberg blew up because it was filled with Hydrogen
http://www.webelements.com/webelements/elements/text/H/econ.html
42. Creation of Elements
Smaller Than Iron
Elements from Helium (He) to iron (Fe)
are made in stars by nuclear fusion.
43. Supernova 2001du
Super giant stars end their lives with a huge explosion called a supernova.
Elements larger than Fe are fused together in supernovas.
http://www.rochesterastronomy.com/snimages/best_img.html
44. Stars Seen From Earth
On a clear night you can see about 6,000 stars without a telescope.
Polaris
http://www.bbc.co.uk/science/space/myspace/nightsky/
(45 & 46.) Polaris
• Polaris is a
super giant
star that
points north.
• Polaris
is used
by sailors
to navigate.
http://www.astro.uiuc.edu/~kaler/sow/polaris-t.html
47. Electromagnetic Spectrum
All the wavelengths of energy from the sun.
Radio Waves, Micro Waves, Infra red, R,O,Y,G,B,I,V Ultra Violet, X-Rays, Gamma Rays
(48 - 50) Waves and Particles from the Sun
Energy waves from the sun include: Heat, (IR), Visible light (VIS)
and Ultraviolet (UV) light.
Particles from the sun
called the solar wind
push comet tails out
and damage satellites.
http://www.solarviews.com/eng/comet.htm
(51& 52). Visible Light
Red, Orange, Yellow, Green, Blue, Indigo, Violet
Low frequency
Long Wavelength
Low energy
High frequency
Short Wavelength
High energy
http://scifiles.larc.nasa.gov/text/kids/Problem_Board/problems/sound/sound_waves2.html
53.
The Source of energy for all bio-geochemical –cycles on Earth is the sun
A powerful M9-class solar storm that unleashed a coronal
mass ejection toward Earth in the early hours of Jan. 23, 2012 (GMT).
Read more: http://www.foxnews.com/scitech/2012/01/31/with-suns-activity-set-to-diminish-is-global-cooling-coming/#ixzz1lEtainph
54. Energy on the Surface of Earth
The sun powers most
bio-geo-chemical cycles on the
surface of the Earth.
Slide 31
The End