Transcript Extra solar Planets

Extrasolar Planets
We ride across the
universe
on a ball of rock
tethered to a star
The Extra Solar Enclopaedia: http://exoplanet.eu/
GC Lupi with
2.5 MJupiter planet
at distance of Neptune
Planet Transits
Algol
Lambda Tau
More than half of the known
stars actually consist of 2 or
more stars in orbit about each
other, and in our own case
Jupiter might be considered a
failed solar companion. There
are presently 13 known multiplanet systems.
Correlation with Metallicity of Star
Mstar = Fe/Hstar / Fe/Hsun
Approximately 210 planets have now
been discovered in orbit about 10
different nearby stars, whose light
spectrum are relatively rich in metals
(metallicity ~ MSol).
Extra Solar Planets by Mass and Distance
Because of the limits of detection,
most of these new planets are
relatively large (similar to Jupiter in
size), but there is a rapid drop off in
examples with masses greater than ~
10Jupiter (the critical mass for
deuterium fusion and the formation
of so called brown dwarf stars is ~
13Jupiter), despite the greater ease of
detecting larger.
Habitable Extra Solar Planets ?
Approximately 1/4 of the new planets that have been discovered fall within the water window in terms
of distance form their suns, and thus temperature, and they or their satellites may well be capable of
supporting life as we know it.
water window
water window
water window
water window
Brown Dwarf
50 light years away
55 AU
First
Planet ?
Mantle Xenoliths
Chondritic Meteorites
lherzolite
chondrite
P
P
Classification of Stony Meteorites
EL (0.8%)
Enstatite
(1.6%)
H (30%)
- opx, no oliv
- 18% Feo
- opx, no oliv
- 25% Feo
- 15% Feo
L (40%)
- 6% Feo
LL (7%)
- 3% Feo
EH (0.8%)
Ordinary
(78%)
Chondrites
(85-87%)
- chondrules
- oliv, opx, Feo
CV (1%)
CO (1%)
STONES
< 30% Feo
(94-97%)
Carbonaceous
(4.8%)
CM (2%)
CI (0.8%)
Achondrites
(10-12%)
- volatile depleted
- refractory lithophile enriched
- refractory inclusions
- volatile depleted
- matrix < 30%
- slight volatile depletion
- matrix > 30%
- volatile-rich
- hydrated silicates
- no oliv or chondrules
Aubrites
- enstatite & Fe alloy
Ureilites
(0.4%)
- shock-melted carbonaceous chondrites?
- olivine + Fe alloy, diamonds
Lunar
- feldspar breccia
SNC
(1%)
- basaltic to ultramafic composition
- shocked, young (1.4 bys)
- Martian rare-gas isotopic ratios
Eucrites
(2.8%)
- basaltic composition
- largely of opx & felds
- assoc: diogenites (opx) & howardites (breccias)
- old (4.5 bys)
MgO
Al2O3
SiO2
CaO
FeO
Total
=
=
=
=
=
=
37.8
4.4
45.0
3.5
8.1
98.8
SiO2 + MgO + FeO ~ 91.1%
Mars
Moon
Venus