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
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 (Rs)
Radius to become a black hole R
s = 2GM/c2
G = gravitational constant M = mass of the body C = speed of light
Object > 3 solar masses become black holes
Wien & Stefan-Boltzman
λmax
= 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
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?