Astronomy 1220
Introduction to the Stars, Galaxies, and the Universe
(1) The Big Picture
Stars are huge balls of glowing gas that create light and heat by nuclear fusion
Planets are relatively large objects that orbit a star. They shine by reflected lig
Midocean Ridge- Place where 2 plates are moving apart, allowing fresh magna to well
up
1.
How do we probe the deep interior of Earth to determine its interior structure?
By monitoring seismic waves
2.
What is the typical density of rocks from Earths crust
1.
Lithosphere- earths crust and a small portion of the upper mantle that make up
the earths plates. Undergoes tectonic activity
2.
Subduction Zone
3.
- place where 2 plates meet and one slides under the other
4.
Secondary Atmosphere- chemicals that compo
1.
Igneous- type of rock formed from molten material
2.
Differentiation- variation in the density and composition of a body
3.
neap tide- smallest tide, occurring when earth/moon line is perpinduclar to the
earth/sun at the 1st and 3rd quarters
4.
Tidal F
1.
high energy astronomy- using X or Gamma ray radiation instead of optical
2.
pixel- picture elements into a 2 dimensional array
3.
seeing- ease with which telescopic observations can be made from Earth, given
the blurring turbulence
4.
background noise-
Element
- matter made up of one particular atom.
The number of protons in the nucleus of the atom determines which element it
represents.
Ion
- an atom that has one or more of its electrons.
Collisional Broadening- broadening of spectral lines due to coll
1.
Cosmic debris
2.
Condensation theory- favored model or solar system formation which combines
features of the old nebular theory with new information about interstellar dust grains,
or condensation nuclei. P 162
3.
Protoplanet
4.
- clump of material, fo
1.
Aurora
2.
- when atmospheric molecules are excited by incoming charged particles from
the solar wind, then emit energy as they fall back to their ground states.
3.
Outer core- outermost part of earths core, believed to be liquid and made of
nickel and
Light
Michael Faraday: 19th century physicist: introduced principle of a field in early
1800s
Light and electromagnetic radiation occur because of the changes in these fields.
Newton invented calculus in the 1600s to understand gravity. He also showed tha
Astronomy Halley's Comet
Halley's Comet is one of the best known short-period comets, comets having a period of less
than 200 years, and is visible from Earth every 75 to 76 years. Halley is the only short-period
comet that is clearly visible to the naked
General Notes Astronomy
General Relativity
If you take the shortest possible path through space-time, you feel no forces
Gravitational potential energy
o GM^2/R
Ratio of Gravitational potential energy to kinetic energy
o 2GM/RC^2
when it equals 1, its a
Chapter 15. Pt. 2
How do we measure stellar masses?
- Mass is harder to measure./
- Newton's version of keepers third law.
- Observe one object orbiting another ,and it requires that we measure both the orbital period and
the average orbital distance of t
The strong absorption of the atmosphere in the ultraviolet (UV) part of the spectrum is
largely because of the Ozone Layer.
The ozone layer in the stratosphere absorbs most of the Sun's dangerous ultraviolet
before it reaches Earth's surface
The layer of
Quantum Mechanics
- the laws of physics as they apply on atomic scales
orbital- one of several energy states in which an electron can exist in an atom
1.
photometer- device that measures the total amount of light received in all or
part of the image
2.
Ch
SampleQuestions
1.WhichofthefollowingisNOTacharacteristicofspiralgalaxies?
A.
B.
C.
D.
anuclearbulge
aflatdisk
ahaloofoldstars
lackofcoldgasanddust
d.Spiralgalaxiesdohaveasignificantinterstellarmedium,notleastbecausespiralarmsare
regionsofenhancedstarform
10.Becauseoftheexpansionofspace,weseealldistantgalaxiesmovingawayfromus,with
moredistantgalaxiesmovingfaster.Anobserverononeofthesedistantgalaxieswouldsee:
A. Allgalaxiesmovingaway,withmoredistantgalaxiesmovingfaster.
B. Allgalaxiesononesideapproaching,an
Chapter 23: Dark Matter and Dark Energy
Wednesday, December 2, 2015
11:04 AM
1
A
B
1
2
2
2
The Universe's Critical Density: crit
Universe has reference density called critical density
Density larger than Euclidean, angles larger than 180 degrees
Density s
1
1
1
2
2
2
Life on the Main Sequence
a Mass determines location on main sequence
b Star's mass determines core pressure and temperature (and rate of hydrogen fusion)
c Higher mass- hotter cores, faster fusion rates, greater luminosities, shorter lives
On
Chapter 21: Galaxy Evolution
Wednesday, November 11, 2015
11:27 AM
Understanding of galaxy formation/evolution<understanding of star formation/evolution
Approach- combining theory with computer simulation
Galaxy "family album"
o
Looking far away- see youn
Chapter 20: Other Galaxies
Monday, November 2, 2015
11:21 AM
Other Galaxies and Foundations of Cosmology
Our Galaxy's Anatomy
a Disk- gas and stars in orbit, old and young, blue white color
b Spheroid
2 Three Basic Types of Galaxy
a Elliptical- spheroid,
Chapter 19: Our Galaxy
Monday, October 26, 2015
11:28 AM
Milky Way- "Via Lactea"- our view of our galaxy
1
2
2
Structure and components
a Edge on view- similar to ours
b Oblique view- not seen directly
i
Spiral arms
ii
Young open clusters
b Terms
i
Halo-
Chapter 22: The Big Bang
Wednesday, November 18, 2015
11:12 AM
1
2
2
The Microwave Background (400,000 yrs)
a Looking far enough away, can see flash of Big Bang- primordial fireball
b 3000K wall of glowing fog 400,000 years after the big bang itself
i
Mar
Distance, Luminosity, Surface Temperature, Size, Mass, Age
Apparent brightness, distance, and luminosity
Stars have a range of brightness
Brightness depends on luminosity (power) and distance
Two stars can look the same brightness, but emit difference amo
White dwarfs, neutron stars, black holes
1
1
1
Discovering Neutron Stars: Pulsars
Grad student Jocelyn Bell- noticed radio pulses from one place in sky
Pulses from spinning neutron star- pulsar
Confirmation from faster pulsars discovered- too fast for a r
The energy source that keeps the asthenosphere in a semi-solid state so that it can flow
slowly is Radioactive Decay.
Which of the following is at the highest Temperature?
Inner Core.
The temperature at Earth's center is almost as high as the temperature
Ch. 15 Part 1
- Stars are born from clouds of interstellar gas, shine brilliantly by nuclear fusions for millions to
billions of years, and then die, sometimes in dramatic ways.
- Stars form in great clouds of gas and dust, and each one begins its life wi
Chapter 5 Astronomy Notes:
5.1 Light in Everyday Life
How do we Experience light?
- Light is a form of energy (skin can absorb heat from sunlight).
- Greater warmth means more molecular motion, thus sun must be transferring its energy to the
molecules in
Astronomy Notes: The Sun
Why was the Suns energy source a major mystery?
- In the late 19th century astronomers came up with an idea that seemed more plausible, at least
at first They suggest that the Sun generates energy by slowly contracting in size, a
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