Project Report on Astronomical Telescope
Telescope - Introduction
In day to day life, we come across many gagets, you might have seen some persons wearing glasses or spects. Have you ever thought about the function of such glasses ? The glasses which are mainly used for curing problems such as shortsighteadness or longsightedness etc. are called lenses. These lenses can also be used in many a ways, for example these are used in telescope, microscope eye lenses, binoculars etc.
In this investigatory project we shall discuss one of the uses of arrangement of lenses i.e. we shall discuss about the telescope.
Telescope is used for seeing distant objects such as stars, planets etc. Let us see their function, how they can bring a thing near to us.
An astronimical telescope is an optical instrument which is used for observing distinct images of heavenly bodies like starts, planets etc.
It consist of two lenses, the objective lens O, which is of large focal small aperture. The two lenses are mounted co-axially at the three ends of two tubes. The distance between these lenses can be adjusted using a rack and pinion arrangement.
In normal adjustment of telescope the final image is formed at infinity. A parallel beam of light from an astronomical object is made to form on the objective lens of the telescope. It forms a real, inverted and diminished image of the object. The eye piece is so adjusted that A'B' lies just at the focus of the eye piece. Therefore a final highly magnified image is formed at infinity. The final image is eract with respect to A'B' and is inverted with respect to the orject.
However, in astronomical telescope, final image being inverted w.r.t. the object does not matter, as the astronomical object are usually spherical.
Magnifying Power of an astronomical telescope is normal adjustment is defined as the ratio of the angle subtended on the eye by the final image of the angle subtended on the eye, by the object directly when the final image and the object both lie at infinite distance from the eye.