Understanding Celestial Movement And; Using Setting Circles P34 - NATURE & DECOUVERTES mizar LUNETTE 114/900 Mode D'emploi

with up to 228x magnification. However, generally speaking, lower magnification between 25x and
180x will be the maximum admitted.
If you use the model 114/900 on a regular basis, it is advisable to have an assortment of four or five
eyepieces. For example, a set of eyepieces of 40mm, 25mm, 12.5mm, 9mm and 6mm will provide a
respective magnification range of 22.5x, 36x, 72x, 100x and 150x.
A very high quality Barlow lens will double the magnification with each eyepiece.
For planetary observations, advisable eyepieces are:
25mm, 12.5mm, 9mm and 6mm.
For deep sky observations, advisable eyepieces are:
25mm and 40mm.
MAINTENANCE
As with any high quality optical instrument, you must clean the mirrors or lenses as infrequently as
possible. Aluminium coated mirrors, particularly, should only be cleaned when absolutely necessary.
Never touch the reflective surface of the mirrors. A little dust on the surface of a mirror will only lead
to negligible degradation of the quality of the image, and should certainly not be considered a reason
to «clean» the surface. If the cap is replaced on the telescope after every session of observation, once
the interior of the tube is completely dry, it will not be necessary to clean the optics.
ALIGNING THE OPTICS (COLLIMATION)
(FIG 7)
All Mizar 114/900 telescopes are optically aligned in the factory. This refers to the collimation of the
mirrors. It is highly improbable that you will need to realign the optics on your instrument. However,
if the telescope does require the optics to be adjusted, call a specialist who will collimate your teles-
cope.

UNDERSTANDING CELESTIAL MOVEMENT AND

COORDINATES
Due to the Earth's rotation, celestial bodies appear to move from East to West, following a curved tra-
jectory. The path that they follow is known as the line of Right Ascension (RA). The angle between the
celestial body and the celestial equator is called Declination (Dec).
Right Ascension and Declination are analogous to the coordinates system (latitude, longitude) used
on the surface of the Earth.
USING SETTING CIRCLES
Once the poles have been aligned, the setting circles on the equatorial mount (FIG 4) can help you to
locate celestial bodies that are not very visible, and that you would not discover through direct visual
observation.
The planets in the solar system: Mercury, Venus, Mars, Jupiter and Saturn are visible to the naked eye,
you will not need to use the setting circles to locate them.
Setting circles are only needed to locate certain objects in the deep sky (that are invisible to the naked
eye). However, for this, you must have aligned the poles beforehand, with absolute precision, which is
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