What is a circumpolar star?
a star that always remains above your horizon
What makes the North Star, Polaris, special?
It appears very near the north celestial pole
You are standing on Earth's equator. Which way is Polaris, the North star?
on the northern horizon
By locating the north celestial pole (NCP) in the sky, how can you determine your latitude?
The altitude of the NCP is the same as your latitude.
the celestial equator is
a pojection of earths equator into space
horizons altitude =
zenith is at
90 degrees altitude
angualr sizes with a fist =
angular size with fingers spread apart is
one finger =
earth rotatesd from
west to east and makes the celestial sphere appear to rotate around us from east to west
stars that circle or only loop above the horizon are
some stars only make a loop under the horizon and are
other stars rise in the
east and set in the west
the horizon slices through the celestial sphere at an angle tot the equator
causing the daily circles of sdtars to appear tilted in the local sky
the local sky at sydney austraila is
34 degrees latitudde
the local sky at the north pole is
90 degreees latitude
celestial sphere at the north pole
would only see half the celestial sphere, no star rises or sets, they are all circumpolar
celestial sphere at earths equator
all stars rise and set, the celestial spheres are on the northern and southern horizon, would see all of the celestial sphere over the course of a day
celestial sphere somewhere between P and E
some stars are circimpolar, some rise in east and set, and some never rise, one celestial pole is above te horizon, the altitude of the celestial pole is equal to the latitude of your location