Points and circle of reference

2. Any point on the earth's
surface is the direction of
Gravity at that point.

3.  The point above the observer that
is directly opposite the nadir on
the imaginary sphere against
which celestial bodies appear to
be projected. (Highest Point)
 The point below the observer that
is directly opposite the zenith on
the imaginary sphere against
which celestial bodies appear to
be projected. (Lowest Point)

4. The great circle on the
celestial sphere whose plane
passes through the sensible
horizon and the center of the
Earth.

6. Great circles passing through the
zenith and nadir.

7. A circle on the sky parallel to
the horizon.

9. One of two points of
intersection of the Earth's
axis and the celestial sphere.

11. • An imaginary line around
the Earth forming the great
circle that is equidistant
from the north and south
poles.
• A circle dividing a sphere or
other surface into two
usually equal and
symmetrical parts.

12. Hour Circles are great circles
passing through the north and
south celestial poles .
PVP'

14. Hour angle, in astronomy, the angle
between an observer’s meridian (a
great circle passing over his head and
through the celestial poles) and the
hour circle (any other great circle
passing through the poles) on which
some celestial body lies. This angle,
when expressed in hours and minutes,
is the time elapsed since the celestial
body’s last transit of the observer’s
meridian. The hour angle can also be
expressed in degrees, 15° of arc being
equal to one hour.

16. • Circles parallel to the plane
of the Equator.
• (BKC)

17. An imaginary great circle on the
surface of the earth passing
through the north and south
poles at right angles to the
equator.
(SZ PL)

18. Vertical circle whose
Plane is Perpendicular
to the Plane of the
meridian.
(EZW)

19. • The great circle
representing the apparent
annual path of the sun.
• The plane of the Earth's
orbit around the sun.
• It makes an angle of about
23 degrees with the
equator.

22. Either of the two celestial points at
which the celestial equator intersects
the ecliptic.

23. Either of the two times of the year
when the sun is at its greatest
distance from the celestial equator.

26. Thank You