Download Terminology

Terminology
Key words to survive an astronomy lecture
SI Measurements
• Base units
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Distance:
Mass:
Temperature:
Time:
Current:
Luminosity:
Substance:
• Modifiers
• pico (p)
10-12
• nano (n)
10-9
• micro (u) 10-6
• milli (m)
10-3
• …
• kilo (k)
103
• mega (M) 106
• giga (G)
109
• tera (T)
1012
metre (m)
gram (g)
Kelvin (K)
second (s)
Ampere (A)
candela (cd)
mole (mol)
• Derived units
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Angle:
Frequency:
Force:
Energy:
Power:
radian (rad)
Hertz
Newton (N)
Joule (J)
Watt (W)
m/m
s-1
kg.m.s-2
N.m or kg.m2.s-2
J.s-1 or kg.m2.s-3
Ref:
http://en.wikipedia.org/wiki/International_System_
of_Units
Defined Constants
• Astronomical Unit (au)
• Parsec (pc)
149,597,870,700 m
3.0856776 x 1016 m
206264.81 au
3.2615638 ly
Measured Constants (Pt1)
• Speed of Light (c)
• Year – Julian
• Light-Year (ly)
• Hubble Constant (H0)
• Age of Universe
• Gravitational Constant (G)
299,792,485 m.s-1
365.25 days
9,460,730,472,580,800 m
67.80 ± 0.77 km s-1 Mpc-1
13.798 ± 0.037 Gyr
4.354 ± 0.012 x 1017 s
6.67384x10-11 m3 kg-1 s-2
Solar System Constants (Pt2)
• Solar Luminosity
3.939x1026 W
• Solar Mass
1.9818x1030 kg
• Solar Radius
695,508 km
• Earth Mass
5.9722x1024 kg
• Earth Radius
6,371 km
• Earth Perihelion
147,098,291 km
• Earth Aphelion
152,098,233 km
• Moon Mass
7.3477x1022 kg
• Moon Radius
1,737.5 km
• Moon Perihelion
363,104 km
• Moon Aphelion
405,696 km
• Moon Orbit
384,400 km
• Moon Albedo
11%
Ref: http://solarsystem.nasa.gov
Distance & Angles
• Perihelion / Perigee (Closest)
• Aphelion / Apogee (Farthest)
• Major Axis, Minor Axis, Eccentricity
• Degrees - Minutes - Seconds (DMS)
• 360o (deg) – 1/360
• 60’ (arcmin) per deg – 1/21600
• 60’’ (arcsec) per arcmin – 1/1296000
• Hours / Minutes / Seconds (HMS)
• 24 hours (h) – 15o
• 60 minutes(m) – 1/4oor 15’
• 60 seconds (s) – 1/240oor ¼’ or 15’’
Directions (Earth)
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Altitude
Azimuth
Latitude
Longitude
North, South, East, West
Equator, Tropic of Cancer, Tropic of Capricorn
Meridian
Zenith
Nadir
Pole (Celestial & Magnetic)
Directions (Space)
• Right Ascention
• Declination
• Sidereal Time
• Horizon
• Precession
Observation
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Magnitude (Absolute vs Apparent)
Luminosity
Albedo
Power
Frequency, Wavelength, Period
Red Shift / Z
Rotational Period
Orbital Period
Equinox
Solstice
Spectrum
Stellar Objects
• Star
• Main Sequence Star
• Brown Dwarf
• White Dwarf
• Neutron Star
• Cephid Variable
• Wolf-Rayet
• Pulsar
• Quasar
• Proto-Star
• Black Hole
Stellar Groups
• Binary Star
• Open Cluster
• Globular Cluster
• Galaxy
• Local Group
• Large Scale Structure
Major Bodies
• Planet
• Moon
• Satellite
• Asteroid Belt
• Kuiper Belt
Minor Bodies
• Minor Planet
• Comet
• Asteroid
• Meteor
• Shooting Star
• Solar System
Miscellaneous
• Constellation
• Asterism
• H-R Diagram
Homework
• Area of Circle
• Area of Sphere
𝐴 = 𝜋𝑟 2
𝐴 = 4𝜋𝑟 2
• 𝐺𝑟𝑎𝑣𝑖𝑡𝑖𝑜𝑛𝑎𝑙 𝑓𝑜𝑟𝑐𝑒 𝑏𝑒𝑡𝑤𝑒𝑒𝑛 𝑡𝑤𝑜 𝑏𝑜𝑑𝑖𝑒𝑠
𝑚1 . 𝑚2
𝐹=𝐺
𝑑2
Homework (1.1)
A. For an observer located at the equator, what is the size of the Sun
when observed solar noon (midday) at
1) Perihelion
2) Aphelion
3) Mean distance
B. Repeat the above for the Moon at Lunar noon
1) Perihelion
2) Aphelion
3) Mean distance
Homework (1.2)
A. Calculate the solar powered received by the Earth at
1. Perihelion
2. Aphelion
3. Mean distance
B. Repeat the above for the Moon
1. Perihelion
2. Aphelion
3. Mean distance
C. What is the maximum solar power the Earth could receive from the
Moon?
Homework (1.3)
A. Calculate the force on Earth due to the Sun and express as mean
value plus or minus a percentage.
B. Repeat the calculation for the Moon’s effect on the Earth.