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Coordinates and Time - Coggle Diagram
Coordinates and Time
Time
Solar day
tracking noon & midnight
varies during year
Mean solar time
Universal time
Keep track of time
SI second
Julian date and its variants
Sidereal Day
Earth’s rotation
Tropical Year/Julian calendars/Gregorian calendars
Coordinate systems
Horizon
(Altitude-Azimuth Coordinate)
Center: Observer
Defined by:
Location of Observer
North
Coordinates: Azimuth & Altitude (deg)
location dependent
Equatorial
Center: Earth
Defined by:
Earth’s rotation axis
Ecliptic plane (vernal equinox)
Coordinates: RA (hour) & Dec (deg)
Connection (Images in the celestial sphere)
Ecliptic
Center: Sun
Defined by:
Earth’s orbit
Vernal equinox
Coordinates: Longitude & latitude (deg)
Studying objects in the solar system
Galactic
Center: Sun
Defined by:
Galactic plane
Galactic center
Coordinates: Longitude & latitude
Studying objects in galaxy
Motions
Diurnal Motion of Celestial Objects
The motion of stars
Hour angle
observing stars
Annual Motion
Equinox & Solstice
Zodiac and the visible star
Motions that alter the coordinates
Earth’s Motion
Parallex
Precession + Nutation
Aberration
Stellar Motion
Proper Motion
Atmospheric effect
Refraction
Applications
Intuition for locating an
object for your observation
Look up for information for your star
Figure out when to observe
Hour angle
Figure out where to point telescope
RA & Dec to Azimuth & Altitude
Names for Stellar Objects (charts, catalogs, etc.)