1. Manuals
  2. Brands
  3. Helios Manuals
  4. Telescope
  5. 9877
  6. User manual

Helios 9877 User Manual

Astronomical telescope
Hide thumbs
Table of Contents

Advertisement

Quick Links

®
Astronomical
Telescope
User Guide
WARNING!!
Never point the telescope directly at or near the Sun at any time.
Observing the Sun, even for a fraction of a second, will result in
instant and ir reversible eye damage. Please ensure minors ar
e
supervised by an adult conversant with this real danger when
using telescopes or binoculars.
OPTICAL VISION LIMITED
www.opticalvision.co.uk

Advertisement

Table of Contents
loading

Summary of Contents for Helios 9877

  • Page 1 Telescope User Guide WARNING!! Never point the telescope directly at or near the Sun at any time. Observing the Sun, even for a fraction of a second, will result in instant and ir reversible eye damage. Please ensure minors ar supervised by an adult conversant with this real danger when using telescopes or binoculars.
  • Page 2 However, the resolving power (as it is cor- rectly termed) of even the smallest telescope is awesome: a 60mm telescope is capable of resolving detail as small as a £1 coin at a dis- tance of 2.35 km - nearly 1.5 miles! amateur <...
  • Page 3 ^ The catadioptric: The goal of the telescope designer is to pro- duce an optical system that delivers an image as free from any aberrations (defects) as possible in a package that is compact and manageable.
  • Page 4 The initial assembly of your telescope is best undertaken in daylight with plenty of room to lay out the components and to familiarise with the accompanying images to see how the assembled instrument should look.
  • Page 5 As before, GENTLY release your grip on the tube and note is there is a tendency for one end to rise in the air.
  • Page 6 It is, in fact, a smaller version of the main telescope that is designed to have a low magnification and a wide field of view so that the desired target may be easily located. The...
  • Page 7 Magnification = focal length of telescope focal length of eyepiece For example, a telescope with a focal length of 1000mm used in conjunction with a 7.5mm eyepiece would yield a magnification of 133x (1000÷7.5 and rounded to the nearest whole number), whereas the same instrument used with a 20mm eyepiece would deliver 50x.
  • Page 8 There are variations that I’ll discuss in a moment, but all share the common characteristic that there are two axes about which the telescope can be moved which are perpendicular to one another (see Fig.1, page 10). The first axis permits the telescope tube to be moved from horizontal to vertical and is known as the ‘alti-...
  • Page 9 However, should the observer wish to attempt any form of time exposure with the telescope to photo- graph a faint galaxy, for example, then a dif- ferent type of instrument mounting known as an Equatorial is required.

  • Page 11: Equatorial Mount

    If a choice of o b s e rving location is limited, try to position the telescope for the best view of the southern sky as possible. Adjust the angle on the latitude scale of the...
  • Page 12 Polar axis elevation (altitude) alignment Choose a bright star in the east and locate in the eyepiece field. Establish the current axial motion of the telescope by gently moving the telescope tube back and forth, (rotating east- Polar axis Rotation for...
  • Page 13 +90° when the telescope is aimed at the celestial pole. Use the telescope at its highest power to observe a star whose declination is known.

  • Page 14: Using The Setting Circles

    R.A. circle) The easiest way to use setting circles is to off- set from a known position. Set the telescope on an object whose position is known (i.e. a bright star in a recognisable constellation - such as listed in the appendix).
  • Page 15 The p l a t f o rm on which the telescope is sitting (the E a rth) rotates once every 24 hours under these objects.
  • Page 16 It is as well to note that the constel- lation outlines are entirely arbitrary – the familiar figures of Hercules, Leo and Orion are but three of the eighty-eight groups known to astronomers that are largely the result of the classicists' fertile imaginations.
  • Page 17 For example, just over a handspan above the belt of Orion brings you to the p rominent orange star Aldebaran (pro n o u n c e d 'Al-deh-bah-ran', which means "follower" in Arabic) in the constellation of Taurus, the Bull.
  • Page 18 One word of warning, though – if you have to set your telescope up on tarmac or concrete, especially after a warm day, the ground can reradiate absorbed heat after dark...
  • Page 19 When lens or mirror cleaning does become necessary, use a soft camel-hair brush or compressed air to gently remove the dust. If a telescope's dust cover is replaced after each observing session, cleaning of the optics will seldom be re q u i re d .

Table of Contents