Astronomy:

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Astronomy
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• Here is my powerpoint from last years coaches
  conference. I will be updating it to reflect the
  changes in content in this years rules. Im not
  sure yet how to test 50 teams at States on the
  use of DS9 image viewing software, and wont use
  it at all for regionals.

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Finding celestial objects(hyperphysics.phy-astr.g
su.edu)

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Finding celestial objects( burro.cwru.edu)
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Parallax
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Parallax

• Stellar parallax angle abc
• Parallax angle ½ angle abc
• Parsec distance to a star with 1 parallax angle
• Parsec 31 trillion km (19 trillion miles)
• Parsec 3.26 light years

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Parallax

• Star's distance (pc) 1 / parllax ()
• Useful for stars up to about 100pc

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Magnitude

• Apparent magnitude (m)
• Hipparchus 1 to 6
• Lower numbers brighter
• Absolute magnitude (M)
• Corrected to standard distance of 10pc
• Can be determined form spectra
• Distance modulus m M

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Hertzsprung Russel not vampires
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Stellar Motion
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Red shifting (from the corner of her mouth)
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Hubble Constant

• v Hd
• Ho 74 km/sec/Mpc ( 23 km/sec/MLY)

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Age of universe

• v Hd
• H v/d
• 1/H d/v time
• 1/Ho age of the universe

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Schwarzschild radius (Rs)

• Radius to become a black hole
• Rs 2GM/c2
• G gravitational constant
• M mass of the body
• C speed of light
• Object gt 3 solar masses become black holes

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Wien Stefan-Boltzman

• ?max 0.3/T
• T temperature in Kelvin
• Total energy emitted is proportional to the
  fourth power of the absolute temperature
• A star 2x sun's temperature emits 16x more energy
• 24 16

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Open Clusters

• 100 to 10,000 loosely packed
• Concentrated in spiral arms
• Young
• Hot
• Highly luminous
• Like certain vampires

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Globular Clusters

• In halo around galactic disk
• 100,000 to 1 million tightly packed stars
• Old stars (like Lon Chaney Jr)

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Population I Stars

• Hottest brightest
• young
• In disc, spiral arms
• Relatively high in heavier elements
• In dust and gas formed from

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Population II Stars

• Galactic nucleus and halo
• Older
• Almost entirely H He

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Classification of Galaxies
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Galaxy Classifications

• Elliptical
• practically all old stars
• Some gas and dust
• Normal Spiral and Barred Spiral
• Various ages
• Lots of gas and dust in the disk
• Irregular
• Mostly young bright stars, ionized gas

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More Galaxies

• Lenticular
• Bright, flat disc
• No arms
• No recent stars
• Dwarf
• Low mass and luminosity
• Active Galaxies
• AGN emits lots of energy
• Black hole?

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Distances

• Cephid variables
• Standard galaxies
• Tully-Fisher Relation?
• 21cm spectral line width
• Luminosity of spiral galaxies

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Galaxy Clusters

• Regular
• Compact, high density center
• Mostly elliptical and lenticular
• Many with active galaxy emition
• Irregular
• Our local group
• Looser structure, little central density
• Spirals and irregulars
• Super clusters
• On edges of voids

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Featured Objects

• Where are they
• What are they
• Special characteristics?
• Images?

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