Transcript of DISTANCES ACROSS THE UNIVERSE - CAASTRO ACROSS THE UNIVERSE Dr. Brad E. Tucker Mt. Stromlo...
DISTANCES ACROSS THE UNIVERSE Dr. Brad E. Tucker Mt. Stromlo Observatory, ANU University of California, Berkeley
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Why Do We Need Distances?
Planets – Atmosphere, Life R0g�:fE� Stars – Temperature, Size, Age +0g=)f�#f(c Galaxies – Mass, Dark Matter, Age 0KgU_f1BUf(c The Universe – Matter & Energy, Size, Age, Birth and Death !"gBU�P_f�#f(cfV>�NO
Hubble’s Great Question – The Nebula Zoo
Let’s Shrink Our Solar System
The Sun
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Space is Big!
24cm The Sun
Earth
Pluto
Oort Cloud (Comets)
Alpha Centauri (Nearest Star)
2.58 meters
1.30 km
130 – 365 km
7160 km
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Our Universe
880000000000000000000000 km / 93000000000 light-years
Credit: NASA/WMAP Science Team
Choose Your Distance Measurement!
Brad E. Tucker RSAA Colloquium 31 October 2013
Credit: Richard de Grijs
Pop 1 stars Active star formation High mass stars
Pop 2 stars Low mass stars
Geometric Methods
Non - Stellar Methods
Pop 1 stars Pop 2 stars
Dist
ance
from
Earth
Y
Z
The Cosmic Distance Ladder
Parallax
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Parallax S';
Parallax S';
Further Up the Ladder
Parallax
Cepheids
Cepheid Stars
Credit: ESA
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Distances from Cepheid Stars
Credit: LCGOT
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Hubble Diagram
Hubble 1936
Distance
Velo
city
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Still Climbing Up the Ladder
Parallax
Cepheids
Type Ia Supernova & Baryonic Acoustic Oscillations