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Kedkanok Sitarachu
Dr. Suwicha Wannawichian
Jupiter in our Solar system2
Structure of Jupiter’s Magnetic Field
3
http://www.taringa.net/http://www.faulkes-telescope.com/
4
Io
Europa
Ganymede
Calisto
Galilean moons
Io’s Geological Properties
Joshepshoer.com
8Planetary Magnetic Field and Magnetic Footprint
Kivelson et al., 2004http://lasp.colorado.edu
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vperp decrease
vpar increase
vpar decrease
vperp increase
http://www.planetaryexploration.net
vperp increase
vpar decrease
B increase
vperp decrease
vpar increase
B decrease
Jupiter’s Magnetic field structure
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B
B 0
vperp increase
vpar decrease
vperp decrease
vpar increase
UV imaging by HST/STIS
Main oval
Io’s magnetic footprint
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Io’s orbit
Jupiter plasma equator
Power of emission
Schneider and Tauger 1995
mag
net
ic f
ootp
rint
brightn
ess
distance between Io’s orbit and Jupiter plasma equator
z=0
Apply the fitted equation for other data sets
Io’s magnetic footprint brightness and its system III longitudes
Wannawichian, et al. [2010]
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Observation by CASSINI spacecraft
The variation of plasma environment near the satellite was revealed
First peak of Io’s magnetic footprint emission on Dec 28, 2000
Interception location:116.02 highest plasma density:19.49
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First peak of Io’s magnetic footprint emission in 2001
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Second peak of Io’s magnetic footprint emission on February, 26-28, 2007
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Summarized locations where plasma density are expected to be highest
time Interceptionlocation
highestplasma density
locations
Distance from interception
location
1999 102.44 286.75 184.31
14-16/12/2000 113.08 46.45 66.60
28/12/2000 116.02 19.49 96.53
2001 109.07 46.59 62.48
23-25/12/2007 138.11 5.43 107.68
26-28/12/2007 231.74 59.51 172.23
7-11/3/2007 272.19 147.51 124.67
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Discussion the regions where plasma density is
expected to highest were found to be in different longitudes.
longitudinal distances between interception locations and Io’s longitudes where plasma density is expected to be highest were found to be different in each data set.
It implies that the shape of plasma torus may change over time.
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Conclusion Io’s system III longitudes, at which the
density at plasma equator is expected to be highest, appear to vary at times.
The plasma in the torus appears not to be rigidly distributed.
These results provide direct evidence of the variation of the locations where plasma density is expected to be highest that was indicated by Io’s magnetic footprint emissions.
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AcknowledgementDr. Suwicha WannawichianDevelopment and Promotion of Science
and Technology Talents ProjectNational Astronomical Research Institute
of ThailandMembers of Astronomical Laboratory,
Chiangmai UniversityDepartment of Physics and Materials
Science, Chiangmai University
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Thank you
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Interior of Jupiter
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Planetary Aurora
Clarke et al., 1998, 2004
Clarke et al., 2005
Planets Earth Jupiter Saturn
Bsurface (G) 0.1 4 0.2
Rotation period (hr) 24 9.92 10.7
Distance to magnetopause (Rplanet)
11 RE 45 RJ 21 RS
Auroral brightness (kR) 1-100 10-10,000 1-100
1 kRayleigh (kR) = 109 photon/sec from a 1 cm2 column of the atmosphere radiated into 4steradians
www.nasa.gov,
NASA/Goddard Space Flight Center 1999
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Satellites in this study
www.nasa.gov, www.ultimateuniverse.n
Io Europa Ganymede
Enceladus
Satellites Io Europa Ganymede Enceladus
Diameter (km) 3,630 3,140 5,260 498
GeologyVolcanically active, non magnetized
Icy surface, non magnetized
Icy surface, magnetized
Geologically active, icy surface, non magnetized
Enceladus’ water plumes near its southern pole taken
by the ISS/NAC camera onboard Cassini spacecraft
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Open-loop Alfvèn model and the electron beam
Bonfond et al., (2008)
• Alfvèn waves travel from the interaction region at Io to the torus boundary at high latitude.
•The reflections of Alfvèn waves take place causing some of the waves to be reflected and some to continue into Jupiter’s ionosphere.
Blue: Alfvèn current systemRed: electron beams
• Also the electron beam created at high latitude could be reflected to the opposite hemisphere and create a spot leading the main Alfvèn wing spot.
Gurnett and Goertz (1981), Crary and Bagenal (1997)