Spectral analysis of Saturn Keio Senior High School Earth
Science Club Shun Shinozaki Yutaro Ao Ryosuke Nyui Atsushi Takei
Slide 2 Objectives 1. To investigate the atmospheric element of
Saturn. 2. To calculate the relative velocity between Saturn s ring
and the main body. Slide 3 The spectral image of Saturn Purple the
spectrum of Saturns ring Green the spectrum of the main body We
dispersed the middle of the Saturn as the upper chart. Image source
http://www.astroarts.co.jp/news/2004/ 03/02cassini/index-j.shtml
http://www.astroarts.co.jp/news/2004/ 03/02cassini/index-j.shtml
the slit Date:2006/11/24 Telescope: Takahashi 30cm reflector Place:
Gunma astronomical observatory Slide 4 Why did we need the spectrum
of the Saturn s ring? The ring is mainly composed of ice. Sunlight
is either reflected or passes through the ice We hypothesized that
the spectrum of the ring would be the same as that of the sun.
Consequently, if we compare the spectrum of the main body with that
of the ring, we can find the atmospheric element proper to Saturn.
Slide 5 How to investigate 1. By using makali i PC software, we
digitized the spectrum image of both the main body and the ring in
order to measure their respective brightness. 2. By using BeSpec,
we converted the data to obtain spectral intensity, and then
processed it through Excel. 3. We calculated the spectral intensity
of the main body as well as the ring to fit both spectrums. Then we
divided the body s spectral intensity by the ring s spectral
intensity to get the reflection rate. Slide 6 Result Absolution by
methane 6200 7250 7900 Slide 7 Conclusion As the result of the
analysis, we found the absorption line of methane. We can conclude
that there must be methane in Saturn s atmosphere. Therefore Slide
8 How to calculate relative velocity We compared Body s spectrum
with Ring s to investigate the gaps between them. Then we
calculated relative velocity by using formula of the Doppler
Effect. We compared H wavelength at body with same one at Ring to
investigate gaps between them by using makali i. Slide 9 How to
calculate relative velocity We determined the center of absolution
by H. We found out that Body s minimal value was 870 pixels. Slide
10 How to calculate relative velocity We drew approximate curves,
calculated the local minimum and its coordinates. The gap of
minimal value is... upper Ring:0.57 pixels lower Ring:0.44 pixels
average: about 0.51 pixels one pixel 3.19 wide 3.190.51 1.63
Minimum of absorption line (upper Ring s) Minimum of absorption
line (lower Ring s) pixels original date polynomial expression
original date polynomial expression X coordinate formula of the
Doppler Effect /=v/c( c means the speed of light ) The wavelength
of H is 6562.81 (3.19 0.51)/6562.81=v/300000 v 74km/s Slide 11
Conclusion calculated relative velocity in this investigation about
74 km/s the referred date about 18 km/s A big error in calculation
Why? Because the observation equipment was low dispersion, so we
couldn t observe the Doppler Effect very well. Slide 12 References
Jupiter Spectra Project NASA JPL Spectrum Date Base
http://spec.jpl.nasa.gov/
http://astro.ysc.go.jp/saturn-ring-opening-sun- earth.jpg
http://www.shokabo.co.jp/sp_e/optical/solar/s aturn/saturn.htm
Published by Hamashima book store New Stage Graphical book of Earth
Science Slide 13 Acknowledgment Toshihiko Hamane (Gunma
astronomical observatory) Thank you very much for your great help
!
