Astronomy:

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

Finding celestial objects (hyperphysics.phy-astr.gsu.edu)

Finding celestial objects ( burro.cwru.edu)

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

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

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

Hertzsprung & Russel; not vampires

Stellar Motion

Red shifting (from the corner of her mouth)

Hubble Constant v = Hd Ho = ~ 74 km/sec/Mpc (~ 23 km/sec/MLY)

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

Schwarzschild radius (R s ) Radius to become a black hole R s = 2GM/c 2  G = gravitational constant  M = mass of the body  C = speed of light Object > 3 solar masses become black holes

Wien & Stefan-Boltzman λ 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  2 4 = 16

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

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

Population I Stars Hottest & brightest young In disc, spiral arms Relatively high in heavier elements In dust and gas formed from

Population II Stars Galactic nucleus and halo Older Almost entirely H & He

Classification of Galaxies

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

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?

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

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

Featured Objects Where are they What are they Special characteristics? Images?