A. Observing the Stars
1) Sun (Sol)
(a) only star in our solar system
2) other stars are great distances
(a) Alpha Centauri
(1) next nearest star
(2) 40 trillion km away from
Earth
(i) 4 ˝ light years
3) most spectacular solar flare ever recorded
(a) November 3rd, 2003
(b) propelled by magnetic forces
(c) spans more than 365,000 miles of the
solar surface
4) light year
(a) the distance light travels in one (1)
year
(1) 10 trillion km (6 million
million miles)
5)
constellations
(a) pictures in the sky
(1) a pattern or picture outlined
by stars
(2) Greek, Roman Gods/Goddesses
(3) Mayan, Incan Symbols
6)
star brightness
(a) magnitude
(1) apparent (observed)
(i) temperature
(ii) size
(iii) distance
(2) absolute
(i) brightness you would
see if all stars were placed
at equal distance
from Earth
1. 10 parsecs
– 32.6 light years
7)
color and temperature
(a) spectroscope
(1) breaks light into the colors
of the spectrum
(2) band seen is called the stars
spectrum
(3) provide chemical makeup
(i) dark lines indicate
elements present
(b) red stars – coolest
(c) orange stars
(d) yellow stars
(e) white stars
(f) blue stars – hottest
8)
variable stars
(a) change in stars brightness over days or
hours
(1) Cepheid
(i) undergoes one
complete brightness cycle
(2) Nova
(i) sudden bright change
due to explosion
9)
life cycle of a star
(a) H-R Diagram
(1) Ejnar Hestsprung and Henry
Russell
(2) compares temperature and
absolute magnitudes of stars
(3) Main Sequence
(i) majority of stars
(4) White Dwarfs
(i) small dense stars
size of Earth
(5) Giants and Super Giants
(i) stars with great
diameters
10)
formation of stars
(a) Nebula
(1) huge cloud of gas and dust
(2) gravity forces gas to
contract, forms proto-star
(i) young, not hot
enough for nuclear fusion
(ii) temperature rises
as matter contracts
(3) main sequence
(i) nuclear fusion
begins
(a) hydrogen
combines to form helium
(ii) hydrogen depletes
(4) giant/super giant
(i) core becomes hotter
(ii) nuclear fusion
begins changing helium to carbon
(5)
final stage (affected by
star’s mass)
(i) white dwarf
(a) Sun
(ii) supernova
(a) exploding
star of intense brightness
(i)
neutron star
(a) extremely dense packed neutrons
(b) pulsar – radiates (lighthouse)
(ii)
black hole
(a) region around which no light/mass can escape
(iii)
white hole(?)
(a) opposite of black hole
(b) worm hole
11)
groups of stars
(a) binary star systems
(1) system of two (2) stars
orbiting each other
(b) multiple star systems
(2) groups of three (3) or more
stars
(c) star clusters
(1) open cluster
(i) irregularly shaped
group of stars
(2) globular cluster
(i) spherically-shaped
group of stars
B. Galaxies
1) elliptical
(a) pumpkin-shaped; evenly bright
(b) few dark nebula
2) spiral
(a) milky way
(1) bright center
(2) radiating arms of stars and
nebula
3) irregular
(a) having neither a spiral or elliptical
shape
C. The Universe
1) motion
(a) spectra
(i) spectroscope
(ii) the greater the shift in
spectra, the faster the star is moving
(b) Doppler effect
(a) apparent change of wavelength
occurring when an object is moving
(1) blueshift
(i) shorter
wavelength
(ii) star
approaching
(2) redshift
(i) longer
wavelength
(ii) star
receding
2) Hubble’s law
(a) the further a galaxy is from Earth, the
faster the star is moving
3) Big Bang Theory
(a) comparison of redshifts in galaxy
spectra
(b) 15 million years ago
(i) mix of radiation and
particles
(ii) temperature rose to produce
nuclear fusion
(iii) matter exploded sending
radiation and particles into space
(iv) matter cooled and gravity
collected matter into nebulae
(v) galaxies formed
(1) nebula hypothesis
(i) sun and
planets formed together
(ii) large
collection of gas and dust
(iii) main
mass pulled to center and formed sun
(iv) smaller
clumps of material collided and clumped together,
settling
into one plane
(v) sun began
nuclear fusion causing remaining gas and dust to
be carried away with solar wind
(vi) end of
crater formation |