Astro final

• 1. Systematic study of the world
• 2. A way of knowing about the
• physical world

• - empirical data
• - provisional explanation
• - specific to general

• - earth is always orbiting the sun
• - solar day is longer than
• siderdal day (1/365th)
• - earth rotates one degree in a siderdal day

great circle that divides visible stars from non visible stars

divides east and west runs north south through observers zenith

• - constellations
• - declination
• - azimath and altitude

angle between point on celestial sphere and equator.

• - angle above horizon
• - always less than 90 degrees

planets moving from east to west ; Mars, Jupiter, Saturn

• - planets move in elliptical with sun at focus
• - line joining sun and planet sweeps out equal areas in equal time
• - sideral period squared=cube of distance to sun

• - body at rest will go in straight line
• - rate of change of velocity=mass of body being accelerated
• - force a exerts on force b; b exerts equal and opposite force on a

• - mass attracts other mass in the universe
• - force of one mass exerts on another=mass of two bits and is inversely proportional to the
• distance between them

this is the point perpendicular up or above observer.

• the circular track of the
• Sun's annual path across the sky
• took about 360 days to complete one year.
• Consequently, they divided the circular path into 360 degrees to track each day's passage of the Sun's whole journey.

each element produces its own pattern of spectra lines and with a spectrograph you can see the lines.

400 nm to 700 nm

Oncoming is shorter, outgoing is longer

Wave goes towards person blue shifted and shorter. Wave goes away longer and red shifted.

• 1.More likely to scatter shorter wave lengths.
• 2.Blue light will scatter 60x more than red light.
• 3.Person behind equals unscatter, People below equals scatter.

temp. and area

False

L=(alpha)Area x temperature to the fourth also look on H-R diagram

• 1. surface area
• 2. distance stellar parallax
• 3. temperature spectral type
• 4. luminosity absolute magnitude H-R diagram
• 5. chemical composition
• 6. brightness
• 7. radial veolcity

Brightness and distance Mass is.

• 1. Tell us mass.
• 2. Pair of stars that orbit each other.
• 3. gravitionally bound together

2 nuclei form 1 nucleus and create lots of energy. This needs high temperature, high density, and high speed to happen.

less than 2 solar masses that lets fusion reaction runaway and very exotic

true

Method of determing a star's distance from Earth by measuring its surface temperature, luminosity, and apparent magnitude.

• Stellar evolution is the sequence of changes in the characteristics of a star resulting from the physical processes occurring within it.
• It is the physical “life history” of a star

• 1. Stars may exist for billions of years (e.g. Sun is about 4.5 x 109 years old).
• 2. Humans live for less than 102 years. Meaning that humans can observe less than 1/107(1 10 millionth) of a star like Sun’s life.

• 1. Continuous Spectrum - light like the rainbow
• 2. Absorption Line Spectrum - dark lines on a continuous spectrum starlight
• 3. Emission Line Spectrum - mostly dark, no continuity

• •Physical laws are constant in space
• •Physical laws are constant in time

• Yes Astronomers
• have seen stars that have just arrived on the main sequence, as well as infrared images of gas and dust clouds in the process of forming stars.

As temp. increases energy is emitted at all wavelengths. As temp. increases greater light is emitted at short wavelengths.

Study of the universe as a whole. Knowing how large, how old, has it existed, its struture, and history of it.

An object greater than 25 solar masses whose gravity is so strong that the escape veolcity from it exceeds the speed of light

True.

true

Vision is blocked by dense matter. You look far enough you can't make out what you see other than billions of stars.

• 1.Determined M31 galaxy
• 2. Giant stage stars that are unstabe that get bright or dimmer and expands and contracts over time.

Stable waves that are spiral and don't wrap up in themselves.

Everything in the universe is moving away from us and moving fast.

• Hubble's law
• Star clusters
• cosmic backgroung radiation

Universe began in an exceptionally hot exceptionally small state. As it expanded it cooled allowing nuclei atom, stars, and galaxies to form.

one element and making another element. Star becomes supernova it takes helium and that becomes carbon.

Light is emitted out of poles, beams are intense. Star rotates like a lighthouse and evertime it rotates towards earth a pulse of light will be visible.