Distance ladder so far:

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Distance ladder so far

• Get AU from Keplers 3rd and radar
• Get nearby stars from parallax
• Use standard candles, e.g. Cepeid variables (be
  careful of population)
• Other standard candles...

M f(Period)
know M
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From Nick Strobels Astronomy Notes
Olber-Cheseaux Paradox (1744)
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Hertzsprung-Russel diagram for an open cluster
B-V
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Hyades Open cluster Constellation Taurus
Magnitude 0.5 Angular size 330
Pleides Open cluster Constellation Taurus
Magnitude 1.6 Angular size 110
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Other distance indicators
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Type Ia Supernovae May have a standard
luminosity at peak brightness corresponding to
Mbol -19.6
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SN 1998dh
SN 1998aq
SN 1998bu
Type Ia supernovae are the biggest thermonuclear
explosions in the universe. Twenty billion,
billion, billion megatons. For several weeks
their luminosity rivals that of a large galaxy.
HST
SN 1994D
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From Nick Strobels Astronomy Notes
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v Ho d
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Fluctuations in the cosmic microwave background
radiation
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As of 2001
But globular clusters are at least 12 by
old. Apparently the universe is not simple.
http//www.astro.ucla.edu/7Ewright/cosmology/htm

• Other measures are consistent
• with 12 billion years.
• Globular cluster ages
• Radioactive dating of the elements

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From Nick Strobels Astronomy Notes
Both wave trains are moving at the same speed but
the top has a wavelength three times shorter
than the bottom.
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