Here you will find a variety of information on the optical characteristics of various types of telescopes as well as some of the basic underlying physics behind them. This includes some information that pertains to the preformance degredation of a telescope optical system (for instance, vignetting and air turbulance) and a few concepts of mirror design (the parabolic shape and over/under correction of the primary mirror). I'd recommend starting with the "Optical Paths" section so you can familiarize yourself with some of the basic types and concepts of several of the widely used telescope designs before reading the other sections.
Optical Paths of Various Types of Telescopes
Here is one of the most interesting parts of astronomy and star gazing: the equipment. There are four different types of basic telescope designs that are in use today. One of these, perhaps the most widely known, is the Refractor. The refracting telescope was first utilized for astronomy by Galileo Galilei in 1609, but it was invented by the German Dutch lens maker named Hans Lippershey in 1608 (Zoom Inventors and Inventions). There are also three other types of common telescopes. These include the Shmidt Cassegrain, Maksutov Cassegrain, and the Newtonian Reflector. In terms of design, they all have different advantages and disadvantages (including cost considerations) that have to be taken into account if one were to decide on a particular design to purchase. Ultimately, the physics behind the the different designs will have an effect in influencing a purchasing decision. But before the four different designs are discussed with greater detail, a few technical terms must be introduced and defined.
Central Obstruction - Refers to the secondary mirror ...
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...ope Basics. 18 Nov. 2002
Freudenrich, Craig. How Telescopes Work. How Stuff Works. 18 Nov. 2002
ACEPT W3 Group. The Refraction of Light Part II. 14 Dec. 1999. 18 Nov. 2002
Vignetting Caused by the Limiting Aperature of Various Tubes and Adapters. 18 Nov. 2002
Marvelde, Arjan. A 10'' Newton Telescope. 17 Nov. 2002
VandeWettering, Mark. Telescope Basics. 18 Nov. 2002
The Meade UHTC Group. 19 Nov. 2002
Kirkpatrick, Larry D. and Gerald F. Wheeler. Physics: A World View. Fourth Edition. Harcourt College Publishers: Orlando, Florida, 2001.
5th Feb, 2014. Wolf, Johnathan. " The Spotlights." Wolf, Johnathan. AP Physics B. Barron’s:
Who has not ever, even if just for a brief moment, looked up at a dark but vividly lit starry night sky and wondered how far those seemingly little lights reach, and if that beauty goes on forever, or if it ends at some point. I believe this question has been pondered by mankind since our creation, and early astronomers are proof of this pondering. Telescopes began as a way for these early astronomers to chart the stars and planets and their movements as they searched for more than what just the naked eye could offer them. In the early 17th century, craftsman began making telescopes, though the tools to invent them had been available for centuries before. Early telescope were called spyglasses and needed improvement. Galileo's Optic Tube, also known as the Galilean telescope is an example of the early creation of refracting telescopes. There were a few different makers and models of refractor telescopes but it was soon discovered they could make a better telescope. With the beginning of the 18th century came the reflecting telescope, which is also called a reflector; an optical telescope that uses either a single curved mirror, or a combination of curved mirrors. There are many types reflecting telescopes: there is the Gregorian telescope, the Cassegrain telescope, and the Ritchey–Chrétien telescope. But today, we are going to be talking about one telescope in particular; "the 200 inch Hale Telescope, which for decades stood as the largest telescope on the planet"(1), from 1948 to 1976. The Hale telescope opened up the skies in ways we never imagined.
The Orion Nebula is not a difficult nebulae to find. It can be seen best during the colder months of January and February (Ivan P. 1). It is one of the many more noticeable star patterns in the sky during the winter (Franknoi 1). The three stars in it's center make it easier to find than most (Franknoi 1). If you live in the Northern Hemisphere, you can find the Orion Nebula in the southwest sky between Latitudes 86 and -75 degrees (Ivan P. 1). The Orion Nebula is 1,270 light years away from the earth (Fuller 1). The Orion Nebula is also between Jupiter and the brightest star, Sirius (Fuller 1). The Orion Nebula is fourteen light-years across (Ivan P. 1). If you really want to see the Orion Nebula up close then you need to use the Hubble Space Telescope to view it (Fuller 1). Since the Orion Nebula is so easy to find, it is a useful aid in finding other stars surrounding it including Sirius, Aldebaran, and Procyon (Garza 1). The Orion Nebula was also one of the first nebulae to be photographed (Britannica 1). Henry Drapper was the photographer and took the photograph in 1880 (Britannica 1).
2, Alter Dinsmore, Cleminshaw H. Clarence, Philips G John. Pictorial Astronomy. United States: Sidney Feinberg, 1963.
2. Kirkpatrick, Larry D. and Gerald F. Wheeler. Physics: A World View. ed. 4. Harcourt College Publishers. Fort Worth. 2001.
In 1610 he was one of the first people to use the telescope to observe
The principle behind the refractive telescopes is the use of two glass lenses (objective lens and eyepiece lens) to gather and bend parallel light rays in a certain way so that the image fits the size of the eye's pupil. Light rays is gather through the opening of the telescope called the aperture and passes through the objective lens and refracts onto a single point called the focal point. From there the light rays continue the same direction until it hits the eyepiece lens which also refract the light back into parallel rays. During the process, the image that enters our eyes is actually reverse of the original image and magnified because the size in which we preceive the image.
The Hubble Telescope is the world’s first space-based optical telescope. The Hubble telescope received its name from American astronomer Dr. Edwin P. Hubble. Dr. Hubble confirmed an ever expanding universe which provided the basic foundation of the Big Bang theory. The first concept of the Hubble telescope came from Lyman Spitzer in 1946 who at that time was a professor and researcher at Yale University, Professor Spitzer believed that Earth’s atmosphere blurs and distorts light and a space orbited telescope would be able to surpass this problem. He spent nearly all of his life dedicated to making this concept into a reality. (http://hubblesite.org/the_telescope/hubble_essentials/)
Serway, Raymond A, and Robert J Beichner. Physics: For Scientists and Engineers. United States of
American Institute of Physics. Vol. 1051 Issue 1 (2008). Academic Search Premier.> 224. http://login.ezproxy1.lib.asu.edu/login?url=http://search.ebscohost.com.ezproxy1.lib.asu.edu/login.aspx?direct=true&db=aph&AN=34874307&site=ehost-live.
...roups that have been important to astronomy are the Akkadians, Egyptians, Chinese, Polynesians, and the Greeks. They used astronomy for navigation at sea, creating accurate calendars, making new inventions, and many more things! Some modern jobs in astronomy include Educational, Private industries, National Observatories and Laboratories. Also, some technical advances because of astronomy include many telescopes, tracking programs used by FedEx, and IRAF which is used to analyze computer systems. Even though astronomy is an incredibly interesting field, there are minimum job opportunities. Some of the jobs are included in the following fields: education, national observatories and laboratories, or in private industries. Astronomy has been the key to unlocking many new inventions and by connecting things from the past, to the present, and going into the future.
One thing us as humans have never been able to fully understand is astronomy. Always having an unexplained mystery, astronomy also has served as a way to keep time and predict the future. The word “astronomy” is defined as the study of heavenly bodies, meaning anything in the sky such as stars, galaxies, comets, planets, nebulae, and so on. Many people, if not everyone, is amazed by the night sky on a clear, moonless night.
The refracting telescope is one of many different types of telescope. Refracting telescopes work by refracting the light through an initial convex lens, (known as the objective lens), then through another convex lens (known as the eyepiece lens). These two lenses focus the light into the eyepiece so we can see the image clearly.
The achromatic lens that first appeared in a 1733 telescope made by Chester Moore Hall, John Hadley's production of larger paraboloidal mirrors in 1721, the process of silvering glass mirrors introduced by Léon Foucault in 1857, and the adoption of long lasting aluminized coatings on reflector mirrors in 1932 evolved the telescopes to higher levels of performance and accuracy.