Bresser NATIONAL GEOGRAPHIC TELE-MICRO SET Mode D'emploi page 8

The magnification also depends on the focal width of the telescope tube. This telescope contains a tube
with a focal width of 360 mm.
Examples:
360 mm / 20 mm = 18X magnification
Focus wheel
Look through the telescope eyepiece (3) and hone in on a far away object that you can see well (for in-
stance, a church tower). Focus in on the object with the focus knob (1) in the way shown in Fig. 3.
Technical data:
• Design: achromatic
Notes on cleaning
• Clean the eyepieces and lenses only with a soft, lint-free cloth, like a microfibre cloth. To avoid scratching
the lenses, use only gentle pressure with the cleaning cloth.
• To remove more stubborn dirt, moisten the cleaning cloth with an eyeglass-cleaning solution, and wipe
the lenses gently.
• Protect the device from dust and moisture. After use, particularly in high humidity, let the device ac-
climatise for a short period of time, so that the residual moisture can dissipate before storing.
Possible observation targets
The following section details several interesting and easy-to-find celestial objects you may want to
observe through your telescope.
The Moon
The moon is Earth's only natural satellite.
Diameter: 3,476 km / Distance: 384,400 km from Earth (average)
The moon has been known to humans since prehistoric times. It is the second brightest object in the
sky, after the sun. Because the moon circles the Earth once per month, the angle between the Earth, the
moon and the sun is constantly changing; one sees this change in the phases of the moon. The time
between two consecutive new moon phases is about 29.5 days (709 hours).
Constellation Orion: The Orion Nebula (M 42)
Right Ascension: 05
h
Distance: 1,344 light years from Earth
Though it is more than 1,344 light years from Earth, the Orion Nebula (M 42) is the brightest diffuse nebula
in the sky. It is visible even with the naked eye and a worthwhile object for telescopes of all types and
sizes. The nebula consists of a gigantic cloud of hydrogen gas with a diameter of hundreds of light years.
Constellation Lyra: The Ring Nebula (M 57)
Right Ascension: 18
h
Distance: 2,412 light years from Earth
The famous Ring Nebula (M57) in the Lyra constellation is often viewed as the prototype of a planetary
nebula. It is one of the magnificent features of the Northern Hemisphere's summer sky. Recent studies
have shown that it is probably comprised of a ring (torus) of brightly shining material that surrounds the
8
• Focal width: 360 mm
35 (hours : minutes) / Declination: -05° 22' (Degrees : minutes)
m
53 (hours : minutes) / Declination: +33° 02' (Degrees : minutes)
m
/ 360 mm / 12.5 mm = 29X magnification
• Objective diameter: 50 mm