ASTRONOMY: UNIT 1 REVIEW
what does the metric prefix MEGA mean?
million
what is the limit of the distance calculation supernovae
millions of l-y
how would you take 0.000234 from standard to scientific notation?
moving the decimal point to the right 4 times (-4) -- 2.34x10^-4
when converting to scientific notation, would moving the decimal to the right make a positive or negative exponent?
negative
what does the metric prefix KILO mean?
thousand
How do you move between the different size units?
- converting from a larger to smaller unit: multiply (km to m -- multiply by 1000 bc there's 1000m in 1km) - smaller to larger: dividing (by factor)
what is the relationship between distance and parallax angle?
- far away: small parallax angle - close in: BIG parallax angle
what are the base units for mass, volume, and temperature?
- mass: grams - volume: liters - temp.: kelvin
what is one thing to remember when converting between the different values for distance?
- smaller to larger unit: multiply - larger to smaller unit: divide
How do you set up Hubble's law to calculate the age of the universe?
1. Hubble formula: d = v/H(low expo)0 2. standard velocity formula: use d = vt to substitute vt = v/H0 3. Solve for t: t = 1/H(low expo)
what are the different units used for distance in astronomy?
1. km - kilometers 2. AU - average distance earth to sun 3. light year - distance light travels in 1 yr 4. parsec - parallax-seconds 5. megaparsec - 1 mil parallax-seconds
what is the correct format of 1600 in scientific notation?
1.6 x 10^3
what does the metric prefix MILLI mean?
1/1000, one thousandth (10^-3)
what is the limit of the distance calculation cepheid variables
10+ thousand l-y
what is the limit of the distance calculation parallax?
1000 l-y
How are Doppler's law and Hubble's law are related?
Doppler gives velocity, which is plugged into Hubble to give us distance
what is the relationship between a galaxy's distance and velocity that was found by Hubble?
Farther away a galaxy is, the faster it is moving
How luminosity can be used to find distance?
Inverse square law - Luminosity fades with distance^2 - Stars of same luminosity, one 4 times farther away will look 1/16 as bright as the closer star
How to use scale and displacement on photos to find parallax angle?
Use the given scale and measure displacement: multiply scale by the measured displacement = the parallax angle
what is the cosmic distance PARALLAX?
apparent change in position of a star caused by a change in position of the earth
How would you take 12.5 from standard to scientific notation?
by moving the decimal point one to the left (1+) -- 1.25x10^1
what id Doppler's law?
change in wavelength (or frequency) caused by the movement of whatever is transmitting the wave
How can you use parallax formula to calculate distance?
d = 1/p
what is the limit of the distance calculation hubble's law
edge of the universe
what is hubble's law?
father away a galaxy is, the faster it's moving
what is the limit of the distance calculation radar/laser?
inner solar system
when converting to scientific notation, would moving the decimal to the left make a positive or negative exponent?
positive
