easy to guess that the telescope - an optical device for observing celestial bodies.Indeed, its main task is to collect the emitted electromagnetic radiation of a remote object and send it to focus, where a large image is formed or amplified signal.Today there are many different telescopes - from home that can get everyone to high-precision, such for example as "Hubble", able to look at the millions and billions of light-years deep into the universe ...
little history
Adoptedtake that first appeared in 1609 two-lens telescope invented by Galileo Galilei.However, it is not.A year earlier, the Dutchman Johann Lippersgey wanted to patent his device consisting of a lens inserted into the tube, to which he gave the name "telescope", but was refused because of the simplicity of the design.
Even earlier, at the end of the XVI century, the astronomer Thomas Digges was trying to watch the stars through the concave mirrors and lenses.However, the idea has not been brought to its logical conclusion.Galileo also just happened to be "at the right time in the right place": Aim Lippersgeyya at the sky, he discovered mountains and craters on the Moon and many other interesting things.That is why he is considered the first astronomer who used the telescope.This gave rise to an era of refracting telescopes.
kinds of optical equipment
Subsection optical telescopes on the types can be based on the basic type of element that collects light on the mirror, lens and mirror-lens (combined) devices.Each of these has its own advantages and disadvantages, so when choosing a suitable system should take into account several factors: the conditions and purpose of observation, the requirements for size, weight and portability, price and so on.Let us try to understand in more detail what the telescope, and what are the main characteristics are the most popular of his views.So, it looks like a telescope?
refractor refractor
These telescopes are used to zoom in the lens, which due to its curvature collect light.Just as in the other optical devices (cameras, microscopes and the like. D.), All the lenses are assembled in a single device - the lens.
Currently refractory telescopes are used mainly by amateurs, as calculated for observation only close the planets and the moon.
Advantages:
- relatively simple construction, reliability and ease of use.
- not require special maintenance.
- Excellent color reproduction in apochromatic performance and good in achromatic.
- excellent for observing double stars, planets, the Moon, especially at large apertures.
- fast thermal stabilization.
- lens requires no adjustment as the manufacturer still is adjusted in the production.
Disadvantages:
- Compared with katadioptrikami and reflectors have a higher cost per unit of the diameter of the lens.
- Practical largest diameter aperture limited cost and cumbersome.
- Because of restrictions on the aperture, usually refractors less suitable for observing distant, faint objects.
mirror reflecting telescope
Reflector telescope - an optical device, which performs the function of the light-harvesting lens mirror.The main mirror may be of small diameter (spherical) or large (PAR).
Advantages:
- katadioptrikami compared to refractors and the unit value of the diameter of the aperture below.
- compact and convenient for transportation.
- Due to the relatively large aperture, wonderful work in observations of distant and faint objects: star clusters, nebulae, galaxies.
- no chromatic aberration.Images are bright, with low distortion
Disadvantages:
- on thermal stabilization time is required, because of the massive glass mirror.
- image slightly distorted because of the open pipe, unprotected from the warm flow of air and dust.
- periodically require adjustment of mirrors, which during operation or transportation may be lost.
mirror-lens or Catadioptric
catadioptric telescope - an optical device, which dropped various types of image distortion due to the use of mirrors in them, along with corrective lenses.Due to the fact that the light is reflected inside the tube a few times, the focus can be long.Some models are able to capture an image.If used for this purpose catadioptric telescope, photos turn out quite good.
Advantages:
- aberration correction high.
- excellent for observing both close objects such as the moon, and the objects in deep space.
- closed pipe maximum protection from dust and warm air streams.
- compared with reflectors and refractors with equal aperture saved greatest compactness.
- As compared with refractor value larger apertures significantly lower.
Disadvantages:
- relatively long thermal stabilization.
- aperture value is greater than that of the reflectors.
- Self adjustment difficult due to the complexity of the design.
modern space telescopes
come a long way (starting with the telescope of the XVII century and ending automatic space giants), the telescope has opened huge opportunities to study the night sky.But there are many factors that prevent anyone, even the most powerful ground-based telescopes to conduct research.These may include both illumination and turbulence, and the most banal clouds.Orbital space station in this plan have an enormous advantage, because they can work around the clock in all weather conditions, transmitting images without any atmospheric distortion.One such station - "Hubble" Space Telescope.Photos made by his optics, perfectly reflect the most distant objects in the Universe, billions of kilometers distant, allowing astronomers to discover new stars, planets and galaxies.
