Download Our Star, the Sun

Our Star, the Sun and
The Nature of the Stars
Chapter 18 & 19
Sun
•Energy source
•Interior structure and helio-seismology
•Surface features
•Atmosphere of the sun
Nature of the stars
•Distance – parallax
•Motion of the stars – proper and radial motion
•Spectral types
•H-R diagram
•Binary systems
By the way, how is your research going?
Chapter 16
By reading this chapter, you will learn
16-1 The source of the Sun’s heat and16-8 The nature of sunspots
16-9 The connection between
light
sunspots and the Sun’s
16-2 How scientists model the Sun’s
magnetic field
internal structure
16-10 How magnetic reconnection
16-3 How the Sun’s vibrations reveal
can power immense solar
what lies beneath its glowing
eruptions
surface
16-4 How scientists are able to probe
the Sun’s energy-generating core
16-5 Why the gaseous Sun appears to
have a sharp outer edge
16-6 Why the upper regions of the
solar atmosphere have an emission
spectrum
16-7 The relationship between the
Sun’s corona and the solar wind
Steps to Fuse Hydrogen
into Helium
Step 1: 2 protons or
hydrogen nuclei, combine
to form a 2H. also
produces a neutrino (n ), a
neutral, nearly massless
particle, & positron (e+).
This positron encounters
an electron (e-),
annihilates to produce
gamma-ray photons ( ).
Step 2: 2H combines with
a third proton, forming an
isotope of helium (3He)
and releasing another
gamma-ray photon.
Step 3: 2-3He nuclei
formed 4He and releasing
two protons. The gammaray & KE, are the source of
the Sun's energy.
Energy source of the sun
H fusion
PP chain
Neutrino
detection?
Interior structure
How are you doing?
• The sun is the largest object in the solar
system: the sun’s diameter is about __ than
Earth.
a) In order of million times larger, b) 1300 times
larger, c) 100 times larger, d) 10 times larger
• The sun generates energy at:
a) The surface ( photosphere), b) anywhere in the
sun, c) only at the core which takes up about
50% in radius, d) none of the above
• Sun’s energy source is
a) Hydrogen fission, b) hydrogen fusion, c) helium
fission, d) helium fusion, e) uranium fission
Click “enter” to review your answers
C, d,b
Watch the Solar blast video
• http://video.nationalgeographic.com/video/
player/science/space-sci/solarsystem/solar-blast-sci.html
• Is the sun a peaceful ball of gas?
• How hot is the core of the sun?
• What are / what causes the sun spots?
• What is a solar blast? Effect on earth?
Photosphere
Photosphere
Zeeman effect
Differential rotation
and
magnetic field line
Go to the SOHO link.
Is there any significant sun spot today?
• http://sohowww.nascom.nasa.gov/sunspot
s/
Temperature graph (2)
Coronal mass ->solar wind
Chromosphere
1. The convective current on the sun creates: a)
granulations, b)Sunspots, c) solar wind, d) tide on
Earth
2. Who was the first person to observe the sunspots?
a) Hubble, b) Aristotle, c) Hipparchus, d) Galileo
3. What are sunspots? a) Permanent marking on the
sun’s surface. b) higher temperature than
surroundings, c) lower temperature than
surrounding. d) made of different material than
surrounding. (like storms on Jupiter)
4. Zeeman effect measures:
a) temperature, b) mass, c) electric field, d) magnetic
field
Click “enter” to review your answers
A,d, c, d