Bresser Junior 70/900 EL, Operating Instructions Manual

Page: 25 / 172

25
EN
1. Technical data:
• Double-lens system (achromatic)
made of glass
• Alt-azimuth mount with equatorial
wedge (Optimised mounting system
with flexible shafts)
• Magnification: 45x – 337.5x
• Lens Diameter: 70 mm
• Focal Length: 900 mm
• 3 eyepieces: K-20 / K-12 / K-4 mm
• Diagonal Mirror
• 6x25 Viewfinder
• 1,5x Erecting lens
• Adjustable Aluminium Tripod
2. Possible objects for observation:
We have compiled and explained a number of
very interesting celestial bodies and star clus-
ters for you. On the accompanying images at
the end of the instruction manual, you can see
how objects will appear in good viewing condi-
tions through your telescope using the eyepie-
ces that came with it.
The Moon
The moon is the Earth’s only natural satellite.
Figure 19)
Diameter: 3.476 km
Distance: approx. 384 401 km
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 ang-
le 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).
Orion Nebula (M 42)
M 42 in the Orion constellation (Figure 20)
Right ascension: 05:32.9 (Hours: Minutes)
Declination: -05:25 (Degrees: Minutes)
Distance: 1.500 light years
With a distance of about 1500 light years, the
Orion Nebula (Messier 42, abbreviation: M 42) is
the brightest diffuse nebula in the sky – visible
with the naked eye, and a rewarding object for
telescopes in all sizes, from the smallest field
glass to the largest earthbound observatories
and the Hubble Space Telescope.
When talking about Orion, we‘re actually refer-
ring to the main part of a much larger cloud of
hydrogen gas and dust, which spreads out with
over 10 degrees over the half of the Orion con-
stellation. The expanse of this enormous cloud
stretches several hundred light years.
Ring Nebula in Lyra constellation (M 57)
M 57 in the Lyra constellation (Figure 21)
Right ascension: 18:51.7 (Hours: Minutes)
Declination: -+32:58 (Degrees: Minutes)
Distance: 2.000 light years
The famous Ring Nebula M 57 in the constel-
lation of Lyra is often viewed as the prototype
of a planetary nebula; it is one of the magni-
ficent 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 central star (only visible with larger tele-
scopes), and not of a gas structure in the form
of a sphere or an ellipsis. If you were to look at