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Coordinates and Time - Coggle Diagram
Coordinates and Time
Time
Solar Time
Ture or Apparent Solar Time
Mean Solar Time
EqT = TST - MST
Univsersal Time (UT) is Greenwich Mean Time
Dynamical Time
Dynamical Time: TDT = UT + ΔT
Barycentric Dynamical Time
TAI
UTC: Leap Seconds
UT1
Sidereal Time
Sidereal Time is based on the Earth's rotation relative to the stars
Solar Day is 4 min or 0.986° longer than sidereal time
Julian Date
Calculate JD since 2000: JD=2451544.5 + 365 * (Y - 2000) + N + L
Began with January 1, 4713BC
Heliocentric Julian Date ( earth orbit motion considered)
Conparsion between Julian and Gregorian Calendar
Coordinates
Alt-az System
Observer-Based Azimuth and Consistent Altitude
No Permanent Description
Equatorial Coordinates
Dec, RA, and Vernal Equinox
Permanent Description despite of Earth Rotation
Other Coordinates
Ecliptic System
Galactic System
Conversion from one to another