Orion 9533 - Manual (Page 25)

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Resolution: The minimum detectable angle an optical sys-
tem can detect. Because of diffraction, there is a limit to
the minimum angle, resolution. The larger the aperture,
the better the resolution.
Right Ascension (RA): The angular distance of a celestial
object measured in hours, minutes, and seconds along
the Celestial Equator eastward from the Vernal Equinox.
s ‑
Sidereal Rate: This is the angular speed at which the Earth
is rotating. Telescope tracking motors drive the telescope
at this rate. The rate is 15 arc seconds per second or 15
degrees per hour.
t ‑
Terminator: The boundary line between the light and dark
portion of the moon or a planet.
u ‑
Universe: The totality of astronomical things, events, relations
and energies capable of being described objectively.
V ‑
Variable Star: A star whose brightness varies over time due
to either inherent properties of the star or something
eclipsing or obscuring the brightness of the star.
W ‑
Waning Moon: The period of the moon’s cycle between full
and new, when its illuminated portion is decreasing.
Waxing Moon: The period of the moon’s cycle between new
and full, when its illuminated portion is increasing.
Z ‑
Zenith: The point on the Celestial Sphere directly above the
observer.
Zodiac: The zodiac is the portion of the Celestial Sphere that
lies within 8 degrees on either side of the Ecliptic. The
apparent paths of the Sun, the Moon, and the planets,
with the exception of some portions of the path of Pluto,
lie within this band. Twelve divisions, or signs, each 30
degrees in width, comprise the zodiac. These signs coin-
cided with the zodiacal constellations about 2,000 years
ago. Because of the Precession of the Earth’s axis, the
Vernal Equinox has moved westward by about 30 degrees
since that time; the signs have moved with it and thus no
longer coincide with the constellations.
appendix B ‑
rs‑232 connEction
You can control your StarSeeker telescope with a computer
via the RS-232 port located on the computerized hand control
and using an optional RS-232 cable (Celestron #93920). The
telescope can be controlled using popular astronomy soft-
ware programs, such as Starry Night
™ Pro.