Inspecting Sunlight --- Introduction to Astronomy

0. Introduction : Different Faces of the Sun

Our Sun radiates energy in a wide range of wavelength.








another plot
Spectrum shows relative strength of different components of light.

Solar spectrum contains a wealth of information about the physical state of the Sun (outer layer of the Sun).

1. Your mission in this workshop.

(1) Build your own spectrograph. --- Understand how it works.

(2) Observe the solar spectrum and find some absorption lines. --- one of the powerful methods of Astronomy

Before you start ...

• How to get spectrum :     method 1      method 2
• Diffraction grating (we use today) : 1000 groves/mm. how it works
• Lights emitted from very close point sources interfere each other.

Work time!

• a sheet of paper for cake box,
• grating film (1000 lines/mm),
• materials for decoration (if you would like ...).

Observe the solar spectrum and find absorption lines.

• Spectrum has two components : Continuum v.s. Lines.
• What are absorption lines?
• These lines hold information of the absorbing material !!

2. Introduction to Astronomy (Spectroscopy).

• Close look at Sun's surface.
• Examples of solar spectral observation :
  • case 1      ---------- Doppler effect
  • case 2      ---------- Zeeman effect
  • case 3      ---------- Plank's law

3. Wrap-up.

• Major in physics,
• Major in Engineering.