Download ExoPlanet search

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Exoplanet detection (500+)
Gravitational attraction between a stellar mass
(sun) and planets (bigger the better, why?)
2 detected exoplanets
to scale for planet orbital makes sun’s position wobble about barycenter.
radius (planets not to
Big question is: How many planets are in lifescale!)
zone where liquid water is stable?
Life zone is where a sun’s luminosity and a
planet’s orbital radius are correct: the green
zone below. The red zone is too hot (Mercurylike) and the blue zone is to cold and makes
gaseous planets (Jupiter-like)
Our solar system to scale
for Jupiter and Saturn
orbital radius
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Exoplanet detection methods
Transit method: light dims
Direct observation infrared
Radial velocity wobble (Doppler shift)
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Exoplanet detection via gravity causing sun wobble
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Kepler mission (launched 2009): watching 100,000 nearby stars. We will know
statistical probability of earth-like planets (liquid water) in 4 years
The Kepler-scope: measure 100,000 stars
brightness (photometry) at same time
(wide view field) to find planets
The local structure of our Galaxy, the Milky
Way. The stars sampled are similar to the
immediate solar neighborhood. Young stellar
clusters, ionized hydrogen (HII) regions and the
neutral hydrogen (HI) distribution define the
arms of the Galaxy.
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3,000 light-year search of stars in Sagittarius Arm
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Stellar mass (our sun masses)
Predicted Exoplanet detectability
Planet orbit (earth-sun distance (AU))
Terrestrial inner-orbit planets
•50 planets if most have R ~ 1.0 Re
•185 planets if most have R ~ 1.3 Re
•640 planets if most have R ~ 2.2 Re
Giant inner planets based on reflected light
•About 870 planets with periods less than one week
Kepler’s third law: T2 ~ R3
Giant planets based on transits
•135 inner-orbit planets
•Densities for 35 of the inner-orbit planets,
and 30 outer-orbit planets.
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Suns orbits around 4 million solar mass black hole at galactic
center of milky way galaxy
A black hole has the biggest
gravitational pull of any
object.
The gravity is so strong that
the mass-energy of light is
frozen in time on the event
horizon so that no radiation
is emitted.
Gravity makes time run
slow. At the black hole
event horizon time stops
and all energy-matter
dissapears into the
singularity.
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Galactic core black-hole sun motion for 8 yrs
Gravity is a
busy force
moving stuff
around
rapidly
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Supermassive black holes at center of most all galaxies
Andromeda central SM blackhole
Milky way galaxy center
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Gravity is the force
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