Astronomical Telescopes

A number of optical instruments have been designed using the concept of reflection, refraction, lenses, prisms and many more. Among which the telescope is one. The first practical telescope was invented at the beginning of the 17th century with the use of glass lenses in the Netherlands. 

A telescope is a device that is used to observe objects that are very far away from us. Images of faraway objects are enlarged with telescopes. An objective lens and an eyepiece are used in a basic telescope. The objective lens of a telescope focuses on a parallel beam of light, which then travels through an eyepiece to generate a magnified image.

Telescope

A telescope is an optical tool that uses curved mirrors to collect and focus light from the night sky in order to see distant objects that are not visible to the naked eye.

Because a concave mirror behaves like a convex lens, a telescope can use a concave mirror as its first component or objective. In optical instruments, to make them more portable or to transfer light to cameras and other sensor systems, flat mirrors are commonly used. 

There are numerous advantages to employing mirrors for telescopes instead of lenses. Mirrors may be built far larger than lenses, allowing them to collect vast volumes of light, such as that required to observe distant objects. Telescopes, like microscopes, can also use frequencies of various ranges from the electromagnetic spectrum. Large and highly flat mirrors have very long focal lengths, allowing for considerable angular magnification.

Refractors and reflectors are the two primary types of telescopes. The type of telescope is determined by the objective, which is the part of the telescope that collects light. The target of a refractor telescope is a glass lens. The front of the telescope has a glass lens that bends (refracts) light as it goes through it. The objective of a reflector telescope is a mirror. Light is reflected off (reflected) as it hits the mirror, which is close to the back of the telescope.

The magnifying power of the telescope:

The ratio of the angle subtended at the eye by the image formed at the least distance of distinct vision to the angle subtended at the eye by the object lying at infinity is the magnifying power of a telescope.

M=fofe(1+feD)

fo= the object’s focal length

fe= focal length of the eyepiece

D= least distance of the distinct vision

The telescope is a device used to view distant objects clearly.

It is composed of:

(a) Objective lens

(b) Eyepiece

The telescope is used to offer angular magnification of remote gadgets. The lens has a huge focal length and a very wide aperture compared to the eyepiece because the object can be very far away. Light from a far-off item enters the goal and an actual and inverted photo is created at its 2nd focal point. This photo acts as an eye object.

The telescope is employed to produce an angular magnification of distant objects. It conjointly has an associate degree and objective lens. But here, the target has a massive focal distance and a far larger aperture than the lens. Light from a remote object enters the target and a true image is made in the tube at its second centre of attention. The lens magnifies this image producing a final inverted image. The magnifying power m is that the magnitude relation of the angle subtended at the attention by the ultimate image to the angle which the object subtends at the lens or the attention. Hence:

m≈β/α≈h/fe.fo/h=fo/fe                                                 

In this case, the length of the telescope tube is fo + fe.

Terrestrial telescopes have, additionally, a combination of inverting lenses to make the ultimate image erect. Refracting telescopes will be used for terrestrial and astronomical observations. For example, consider a telescope whose objective incorporates a focal length of one hundred cm and the objective also has a focal length of one cm. The magnifying power of this telescope is m = 100/1 = 100.

Let us contemplate a combination of stars of actual separation 1¢ (one minute of arc). The celebs seem like they’re separated by an associate degree angle of 100 × 1¢ = 100¢ =1.67°

Conclusion

The telescope is composed of two parts, the Objective lens, and the Eyepiece. The telescope is used to observe objects very far from us. The telescope is used to offer angular magnification of remote gadgets. The Indian Astronomical Observatory (IAO) is located in Hanle, Ladakh, India, and is one of the world’s highest optical observatories. Cameras, spectrographs, and interferometers are three types of instruments used by the Hubble Space Telescope to investigate light from the universe.

Various Astronomy equipment, Telescopes, and radio dishes are used from the surface of the planet to review visible light, close to infrared light, and radio waves. connected to those telescopes are varied tools like specially created CCD cameras, a good type of filters, photometers, and spectrometers