S THE OLAR YSTEM

THE
SOLAR SYSTEM
Dr. Sandeep Sahijpal
Department of Physics, Panjab University, Chandigarh
[email protected]
The Creation
An overview and the origin of the solar system
In the beginning…….
The
Context
~ 14 billion years ago
H ~ 76, He ~ 24, Z ~ 0 %
Inside galaxy…..
Interstellar
medium
Cosmic
Cycle
Star formation
Stellar evolution & nucleosynthesis
Red giant
108-10 yr.
White dwarf
106-7 years
Supernova
Sn II
Sn I a
Neutron star/
Black hole
106 years
Wolf-Rayet
Sn I b/c
Formation of solar system
~ 4.5 billion years ago
H ~ 70, He ~ 28, Z ~ 2 %
Solar flare
Sandeep
Sahijpal
Asteroids
Trans-Neptunian objects
Eris
Section
Meteorite
Ca-Al-rich inclusion (CAI)
Chondrules
1 mm
Dating of the early solar system phases
Clocks ....?
238U
decays to 206Pb
Half life ~ 4.47 billion years
235U
decays to 207Pb
Half life ~ 704 million years
Earliest solar system phases
4.566 billion years
How do we know that these are the oldest ???
Radioactive elements
7,10Be, 41Ca, 36Cl, 26Al, 60Fe, 53Mn, 107Pd, 182Hf
(Half lives < 10 Ma)
The Genesis
Astronomical
observations
Astrophysical processes
Pre- & Early- solar system
Early solar system phases
4.56 billion years ago.......
Molecular cloud – an active star formation region
Stellar evolution
Problems with the star formation
Excess of angular momentum
Excess of magnetic flux
Gravitational collapse
Astrophysical Scenario
Protostar  Disc  Bipolar outflows
Parent molecular cloud
Triggered / self induced
formation
Solar nebula
(A disc of gas & dust)
Planet formation
Runaway growth
Terrestial planets & core of the giants
within 10 million years
Accretion & differentiation of Planetesimals
20- 270 km
Fe core
Volcanism
Melt
Un-melted
Accretion of gas by the giant's core
Giant planet migration
The formation of Moon
Onset & rate of accretion of asteroid
Differencess
Composition of asteroids
Thermal evolutionary details
Diverse planetary bodies
The Extrasolar planets
Star 51 Pegasi (1995) by Michel Mayor and Didier Queloz
~529 Planets have been discovered
Thanks