Saturday, December 16, 2006

Schmidt Telescope

The refracting telescope is one of the most common astronomical telescopes in use today. Almost everyone’s idea of a telescope would be that of a refractor, with a long tube and eyepiece and objective lens on the ends.

The refracting telescope is one of the easiest to operate telescopes – just focus it on the distant object of your choice and you will have a clear view of its image.

There is however a telescope that, unlike the refracting telescope, cannot be used for direct viewing of distant objects.

It is the Schmidt telescope or more appropriately called the Schmidt camera, which is actually an instrument mainly for taking pictures or images. The Schmidt telescope is invented in 1930 by Bernhard Schmidt, a well-known optician from Germany.

But like the refractor, the Schmidt telescope is likewise an important instrument as it is reliable for performing astronomical surveys, and for the searches and discoveries of spaces objects such as the comets and asteroids.

One of the most famous Schmidt cameras is the Oschin Schmidt Telescope, which is housed in the Palomar Observatory.

Tuesday, December 12, 2006

Newtonian Telescope - Sir Isaac's Scope Invention

To date, there are already many types of refracting telescope developed and utilized for astronomical and stargazing purposes. A few of these scopes are named after their inventors. One refractor that has a name of a famous astronomer and scientist assigned to it is the Galileo Telescope, named after the genius Galileo Galilei.

This refracting telescope of Galileo is one of the earliest astronomical telescopes and is considered the model of the modern refractors today. Most of the modern, powerful refractors are patterned after the Galileo Telescope.

The reflecting telescope, likewise has many types, and one of the more known is the Newtonian Telescope. An invention of British astronomer and scientist Sir Isaac Newton (1643 to 1727), this scope has a parabolic main mirror and a flat second mirror.

Isaac Newton was very much knowledgeable with the stargazing and research needs of astronomers; this is why he worked on developing this scope. The Newtonian Telescope, when compared to others, is less expensive yet as powerful as the other quality telescopes.

It also provides a short focal ratio, which means a wider and better field of view can be achieved. With the Newtonian telescopes that possess longer focal length, high quality planet views can be achieved.

Sunday, December 03, 2006

Jacob Metius' Refracting Telescope

Many consider Galileo Galilei as the father of the refracting telescope. And while Galileo is actually did not invent the refractor; it was actually the invention of Hans Lippershey.

Yet, many tend to credit Galileo Galilei as the inventor of the refracting telescope because he made great improvement on the telescope of Lippershey, and made a much better, and professionally working astronomical telescope. Galileo’s version of his refractor is popularly known as the Galileo telescope.

While some are yet to be convinced on who between Galileo Galilei and Hans Lippershey should be credited as the creator of the refractor, there is another scientist by the name of Jacob Metius who claimed to be the true inventor of the refractor telescope.

Metius was a Dutch optician and lens maker who was said to have invented a lens bearing instrument that can magnify the image of a distant object. He was said to have presented his invention to the government with the intention of applying for a patent.

Still, it showed that his patent application was done weeks after the application of Hans Lippershey’s patent for his telescope.

The government acknowledged Metius’ work although in the end it was Lippershey’s telescope that was utilized by the government in its astronomical endeavors.

Monday, November 27, 2006

Catadioptric Telescope

What does the Schmidt, Maksutov and the Cassegrain telescopes have in common?

So much about the refracting telescope and the reflector telescope which I have written extensively here. There is another type of astronomical telescope that is a little bit more complicated than these two. If the refracting telescope employ lenses and eyepieces while the reflecting telescope use mirrors, the catadioptric type of telescope uses both lenses and mirrors to be able to focus the light to the desired object. The Schmidt, maksutov and the cassegrain fall under this telescope category.

The catadioptric telescope is like a combination of both the reflecting and refracting telescopes.

What are the advantages of the catadioptric telescopes?

First, it requires less maintenance.

Also, the designs and parts of the catadioptric telescope are simple and easy to produce.

On the other hand, the disadvantage of this type of telescope is that some of the light that is supposed to enter the tube of the scope is blocked by its supplementary mirror.

Monday, November 20, 2006

Refracting Telescope: Legacy of Galileo Galilei

What would astronomy be like if Galileo Galilei was not around to discover the earliest working telescope, which is known as the Galileo telescope and considered the model of today’s refracting telescope.

Actually, everyone knows it was not really Galileo Galilei who invented the refractor telescope, but master optician Han Lippershey. Still, many incorrectly credit Galileo Galilei for the discovery of the refractor telescope – perhaps because of the sheer popularity of Galileo as an astronomer and scientist.

And with a famous astronomer associated with the refracting telescope, the popularity has been rubbed off to the scope. Galileo made some of the most important and significant astronomical discoveries in the history of space science, and his work even led to other equally significant modern discoveries. Eventually this astronomical telescope has firmly established an image of being one of the most important and utilized telescope.

Indeed the refracting telescope is perhaps the first telescope that would pop up into one’s mind whenever he is asked about telescopes. And why not? The refractor is the astronomical instrument that is simple yet very efficient for astronomical researches and star gazing sessions.

Sunday, November 12, 2006

Group Stargazing

As a telescope and astronomy enthusiast, it is great that every star gazing session that you have is done with the company of your astronomer friends. Nothing is better than having someone with whom you can discuss your observations, or perhaps compare your refracting telescope with another.

Star gazing is often more enjoyable and fun when done with groups – whether it be that you and your friends go to a local astronomical telescope observatory for some evening sky observations, or just go mountain climbing to find a perfect spot to set up your refracting telescope or reflecting telescope instruments.

While of course, the advantage of star gazing alone is that you can do it with more concentration - hence it becomes a more productive session. When doing observations by myself I realize that this is when I get much more vivid images. Perhaps it is because I tend to become focused into the work when alone.

Star gazing in groups has one distinct advantage. And that is, you get to share with another person the wonderful experience of seeing the magnificence of almost every sky objects there is.

Saturday, November 11, 2006

Stargazing on a Cloudy Night?

Unless you have a space telescope like the Hubble Space Telescope which seems like going to be forever stationed in space, here on earth you only have either your refracting telescope or a reflecting telescope so you definitely have to worry about clouds that would surely rob you of your magnificent views. (Of course the Hubble Space Telescope, since located in space would not have to worry about clouds.)

A cloudy weather is a spoiler for an otherwise great star gazing experience. Cloud will block any view and there really is nothing we can do about it. Wait for a clear, cloud-free night sky is the best time to set up our refracting telescope and enjoy a nice star gazing session.

Find an ideal place for astronomical observation can be a daunting task, especially if you are living in the city. First of all, the city lights can give you imperfect views of your targeted space objects. If you are a first time telescope user, try to know other amateur hobbyists in your neighborhood who might have determined the best public place for telescope set up.

Have fun - this is a simple yet sound advice. With your star gazing, you might not get the desired results with your refracting telescope or any other astronomical telescope. Usually the objects you are viewing may appear to you as small and not very clear. What do you expect? Most space objects are thousands and millions of light-years away. If you want a more magnificent view, you can train your refracting telescope to the moon anytime and enjoy its very visible features such as the craters and mountains.

Amateur star gazing is more about fun. Gradually you may opt to travel the path of a serious astronomer if it is really your calling.

Friday, October 27, 2006

Stargazing With Your Kids

If you are someone who is seriously into astronomy and an avid star gazer, naturally you would also want to share this exciting out-of-this-world experience of “seeing the moon and the stars” with your family – especially the children.

I am sure you are definitely willing to share with your little tykes your astronomical telescope. Whether it is a refracting telescope or a reflecting telescope, you want them to enjoy and see for themselves the wonders and magnificence of the planets, stars, galaxies and other far away space objects.

If you are going to tag along your kids in any of your star gazing sessions, ideally the telescope that you should use is a refracting telescope. The refractor telescope is an excellent astronomical telescope for your children to use because it is excellent for observing the planets of the solar system and stars. The images that you get are very clear – the kids would definitely be exited with this, wouldn’t they?

This is aside from the fact that the refracting telescope is very easy to operate and maintain – it would not be hard to teach the kids on how to handle it. The refractor is the right instrument for our little tots to use. And just let them use the scope – it will definitely make them more interested in astronomy and star gazing.

Thursday, October 19, 2006

Crane Telescope Observatory

At the state of Kansas, is the Crane Telescope Observatory of Washburn University. Located at Washburn and 17th Avenue, the Crane Observatory is one of the more popular university observatories in the US.

The Crane Observatory houses the popular Warner and Swasey refracting telescope which was built way back in the late 19th century and is considered one of the oldest working refractor telescope instruments in the United States.

The Warner and Swasey refractor telescope is still available for use by the public as it is regularly utilized for regular star and sky gazing and astronomical research.

The Crane Observatory likewise has open house schedules which are usually conducted when permitted by the weather. The observatory also has planetarium programs which are usually held on the afternoon of the first Saturday of every month. The public, especially the astronomical enthusiasts and avid stargazers who wish to participate do not need to register or make reservation.

The astronomical activities and star gazing sessions of the observatory are usually held through the sponsorship of the Washburn University’s Department of Physics and Astronomy.

Monday, October 16, 2006

Green Bank Telescope

I must have discussed every important refracting telescope issues and have likewise featured some of the world’s most popular refracting telescope observatories. Now I guess I have to write articles on other types of telescope such as the radio telescope.

In the state of West Virginia, on Green Bank, Pocahontas County, is where the National Radio Astronomy Observatory can be found. The National Radio Astronomy Observatory houses the popular Robert C. Byrd Green Bank Telescope. More commonly called the Green Bank Telescope, it is recognized as the biggest radio telescope in the world that is completely steerable. The site of the GBT is free from radio transmission, in order for the telescope to function regularly.

The GBT is a 100 meter (3937 inch) telescope, which means its dimension is 100 x 110 meters. The telescope has an individual actuator (small motor) that is used for all of the telescope’s surface panels.

Did you know that the Green Bank Telescope is designed especially to be able to observe the entire heavens above the elevation of 5 degrees? This is one of the special features of GBT.

Monday, October 09, 2006

Refracting Telescope, Reflector and Cassegrain

Here we have discussed mostly about telescopes, the most discussed being the refracting telescope, which is the earliest discovered astronomical telescope.

Easy to set up, requires little maintenance, and one of the simplest astronomical instruments, the refracting telescope is very reliable especially when it comes to observing and studying the moon, the planets and the sun. It is actually excellent in terrestrial viewings.

Next to the refractor telescope is the reflecting telescope which like the former is excellent in observing the planets and the moon. Another advantage of the reflecting telescope is that it is much more portable and compact.

Another type of scope is the Catadioptrics, a popular example of which is the Schmidt-Cassegrain. This type of telescope makes use of a combined lenses and mirrors in order to form the image of whatever object it is focused at.

The Schmidt Cassegrain is one of the most modern telescopes in use today. And it is likewise said to be one of the best multi purpose scope. This telescope succeeded in improving on the combined use of mirrors and lenses, emphasizing on their advantages and eliminating the usual disadvantages when using them.

The Cassegrain is usually used for deep space observation and astronomical photography.

Friday, October 06, 2006

Keppler's Astronomical Telescope

We can only thank Galileo Galilei for his invention of the first astronomical telescope which is the refracting telescope or what is called the Galileo telescope. His refractor was an improvement of the first refractor discovered by a Dutch optician, Hans Lippershey. The fact is, the Galileo Telescope can be considered as one of the most important discoveries and inventions in the field of astronomy.

But in the year 1611, it was the turn of Galileo Galilei’s refracting telescope to become a model to a more improved scope, the Keplerian Telescope, which as invented by the German scientist and astronomer Johannes Kepler.

Johannes Keppler, who is one of Tycho’s outstanding students, used a special type of lenses instead of optical mirrors for the reason that during his time such quality mirrors are not yet available.

The telescope’s convergent mirrors were the trend during Keppler’s time until they were taken over by larger mirrors that were built to capture low intensity objects.

Some more information on Johannes Keppler – Aside from being a scientist and astronomer, he was also a gifted mathematician, a prolific writer of science fiction and an astrologer. He was often referred to by many, especially by as peers, as the world’s last scientific astrologer.

Monday, September 25, 2006

Vassar Observatory

One very popular college observatory in the United States is the Vassar College Observatory, which is located in Poughkeepsie.

The observatory, one very important telescope of which is an 8 inch (or 20.32 centimeters) refracting telescope, is under the maintenance and supervision of the Vassar College Department of Physics and Astronomy.

Aside from the refracting telescope, the observatory also has two more important astronomical telescope instruments, the 32 inch (or 81.28 centimeters) reflecting telescope which is one of the largest reflector telescope instrument in the world and the 20 inch (or 50.8 centimeters) reflecting telescope.

If there is one person significantly associated with the Vassar observatory, she is Maria Mitchell, who is the first director of the observatory. Maria Mitchell is also known as the first female astronomer of the United States.

Vassar astronomy students are very fortunate because as early as their first year of enrolment in the course, they are already given the opportunity to use the observatory for their scientific and astronomical studies and research.

Not only is the observatory available for the college’s student. It is also open to visitors for use of its telescope. Open night is usually a Wednesday night, or Thursday if Wednesday night is not fit for viewing.

Friday, September 22, 2006

Parkes Observatory

In Australia or the Place Down Under is the Parkes Observatory. For a change, we will not discuss here a refracting telescope observatory as the Parkes is different - it is a radio telescope observatory. The Parkes observatory is found near the New South Wales town of Parkes.

The Parkes Observatory is a very popular astronomical center; it is well known for its dish that has been etched in astronomical science history as the one that transmitted the landings of the moon.

This telescope observatory’s main astronomical instrument is the 64 meter radio telescope, which is considered as one of the first and the largest movable dish in the world. The dish’s construction was completed in the year 1961 and up to this day is still operational and used for astronomical research.

As opposed to the refracting telescope which is composed mainly of lenses and eyepieces and gathers images, the radio scope is a large dish that is made mainly of metal. The function of this dish is to collect radio waves from space, hence its name. Usually, the radio waves they pick up and record are those that originated from stellar and other celestial and space objects.

Monday, September 18, 2006

John Craig's Astronomical Telescope

John Craig, a reverend from London, England, dreamed of constructing his own refracting telescope.

And so in the year 1852, the reverend’s dream became a reality. He was able to build his own refractor telescope.

Albeit the tower where the telescope was located was built in only a few months, the scope itself was built after a few years. The site of the telescope is on Wandsworth Common in London.

And during its time, Rev. Craig’s scope was the largest in the world.

Did you know that Rev John Craig does not have affiliation on any astronomical group or society? Still, he was inspired to create his own refracting telescope with the purpose of searching for answers to two questions that plagued his mind. One, if Venus the evening star also has a moon or satellite like the Earth and other planets, and second, if Saturn indeed has its own rings.

John Craig’s refractor telescope became popular soon after it became operational but the fame was short lived as it was discovered that the scope lens of the scope was inferior to be utilized for astronomical purposes.

Monday, September 11, 2006

Mount Stromlo Observatory

If you are searching for an Australian observatory with a refracting telescope as one of its astronomical instruments, you might want to go to Mt. Stromlo in Canberra.

Founded n 1924 is the Mount Stromlo Observatory which can be found just beyond the boundary of Canberra in Australia. Also known as the Commonwealth Solar Observatory, it is part of the Australian National University’s Research School of Astronomy and Astrophysics.

The site of the observatory is on Mt. Stromlo itself. Actually before its establishment in 1924, a telescope was already put up there 14 years earlier used as instruments for atmospheric researches.

The early decades of the twentieth century saw the Mount Stromlo Observatory specializing in atmospheric and solar research and observation. In was only after the second world war that the observatory engaged in the science of astronomy, specifically the study of the galaxies and stars – and at about this time, the observatory was renamed as the Commonwealth Observatory.

Aside from its 66 centimeter (26 inch) refracting telescope, other astronomical instruments are a 188 centimeter (74 inch) reflecting telescope and other smaller sized reflector telescope instruments (50 inch and 30 inch).

Monday, September 04, 2006

Nice Observatory

The Nice Observatory or the Observatoire de Nice is the popular refracting telescope observation facility that is found in this French city. It is strategically located on the summit of Mont Gros, which has a fine view of the city and the Baie des Anges.

The Nice Observatory is recognized as a major European astronomical institution devoted to astronomical researches and studies.

The observatory was a project of banker and philanthropist Raphael Bischoffmein. He initiated its construction in 1879 with the observatory’s architect as Charles Barnier. The world famous Gustave Eiffel was the one who designed the main dome of the observatory.

In 1888, the observatory was able to acquire a 76 centimeter refractor telescope and at the time of its operation was considered as the largest refracting telescope in the world.

However, the year after (in 1889), a better refractor telescope was purchased by the Lick Observatory, replacing the Nice astronomical telescope of the world’s largest.

The site of the observatory is considered as one of the best in Europe. Its park is wide and spacious and covering about an area of 100 acres. It is likewise well protected and maintained by the management of the observatory.

Thursday, August 31, 2006

Paris Observatory

One of the oldest refracting telescope observatories is the Paris Observatory of France. Built in the year 1667, the Paris Observatory is considered an institution when it comes to scientific researches in Physics and Astronomy.

This European astronomical observatory has a long standing constitution which contains its important missions such as scientific researches, imparting knowledge to the general public and scientific collaboration with other countries.

Most of the astronomical researches are on the topics in Astrophysics and Astronomy, specifically the history of sciences, specifically stellar physics (as well as the physics of the galaxies), systems involving the planets, the sun and the solar system and the gravitational waves.

The Observatory is composed of an Institute and a scientific unit and five other scientific observatories. It is also where the International Time Bureau is found until it was dissolved in 1987.

It also owns an 83 centimeter (32.68 inches) refracting telescope and has a solar observatory set up at Meudon, which is 9 kilometers south of Paris, France. Meudon is a commune built on the hills of Seine. Most astronomical observations are done on this place.

Monday, August 28, 2006

A Kid's Refracting Telescope Experience

Ask any kid from Middle School about what he knows about scopes and surely enough he would mention terms like reflecting or refracting telescope or even Galileo telescope.

These astronomical instruments, especially the refractor, are the simplest and easiest to be taught and learned in any science class. These are the scopes that are drawn on cardboards and posted on the wall of the classroom.

If a science teacher would bring his class to a nearby astronomical observatory for a viewing of the planets such as Mars and Jupiter, or the moon's craters or the stars, more often than not, the instrument that they would be using is a refracting telescope.

If a kid is showing some keen interest on knowing more about the heavenly bodies, stars and planets, he would inevitably turn to his parents and bug them for some real, serious scopes for his star gazing activities.

Discount telescope gadgets are available in many scope and optical shop and dealers, and they certainly offer some great refractors with all the nice features - these are perfect for parents who are looking to impress their kid with a refractor that is seeming perfect for him. Nonetheless, it is something that is inexpensive being a discount telescope.

Children who grow up loving astronomy and loving to learn the science, also definitely has the refractor as his first telescope to learn about.

Friday, August 25, 2006

Discount Telescope

Refracting telescope is very popular because it is simple, easy to use and requires little maintenance. It is a favorite scope to use for amateur astronomy.

If you are a stargazing enthusiast or hobbyist who is serious about astronomy and really wanting to buy a good refracting telescope but is on a tight money situation, then you might want to try going for a discount telescope.

Actually, the best refracting telescope is one that's pricey; the more expensive your refractor is, the better and excellent its features are.

The good news is, there are telescope and optical instrument stores that sell discount telescope straight from the factory. This significantly reduces the price of the product, making it affordable to many.

Likewise, there are lots of reliable scope dealers that you may check online on the internet. These online scope shops can provide prospective buyers with a wide array of telescope products that's heavily discounted making it easier on the pocket. All you have to do is to carefully check which shop offers the astronomical telescope that is appropriate for your budget and star gazing requirements.

Wednesday, August 23, 2006

Refracting Telescope: Preferred Scope of Many

It is really a wonder why the refracting telescope has not been manufactured for professional in the last many years. Has it being eclipsed by the more modern and high technology telescope instruments.

For me, the refractor telescope is one of the best, if not the best scope ever discovered.

And despite its simplicity, it is a reliable, scientific instrument that is perfect for stellar, lunar and planetary studies, researches and observations.

Actually, some of the more modern refracting telescope instruments allow astronomers and scientists to view much distant objects such as the nebulae and galaxies. It has immense optical power when it comes to the capacity to gather light.

So why then is the refractor not utilized professionally anymore? Perhaps because of its technical flaw known as the Chromatic Aberration that diminishes its over-all importance and performance as an astronomical telescope. (Chromatic aberration is when fringes of colors appear around an image.)

Or simply because more telescopes of superior quality have since been invented.

Nonetheless, this scope is still the scope of choice for many astronomy enthusiasts and stargazing hobbyists. Even the ordinary man's description of a telescope would very well be that of a refractor.

A word of advice: avoid discount telescope when you wish to own a refracting telescope. When it comes to owning this kind of scope, it is not worth scrimping on money and just buy a discount telescope.

If you are really into serious astronomy and stargazing, save up to be able to buy a more expensive one that has all the features appropriate to your needs.

Monday, August 21, 2006

Few Do's and Don'ts About Your Astronomical Telescope

On trying to have your own astronomical telescope

Instead of contemplating on buying a cheap telescope from the toy section of a department store, go to a reliable telescope dealer and check out inexpensive discount telescope which might be available.

If you are really hard up on money, and can’t afford even a discount telescope, try building a one of your own. Refracting telescope has very few and simple parts – this is the ideal type of telescope that you might want to assemble. Try rubbing in on your kids or brother your interest in astronomy by asking them to assist you in your telescope making.

On proper use of refracting telescope

Always avoid touching the objective lens or eyepiece of your refracting telescope or any scope that you might have.

See to it that the telescope is properly and securely mounted. Correct mounting affords you to have the ideal viewing and star gazing.

After every use, store your telescope in a safe and clean place, away from dust particles. Secure a hood cover for protection if you can.

Put on some lens cap for protection and to keep you from touching it.

Friday, August 18, 2006

Dominion Observatory

In Ottawa, Canada is where we can found the Dominion Observatory, which is patterned to that of the Royal Observatory in Greenwich.

The Dominion Observatory is founded by Frederick King, which also acted as the observatory’s chief astronomical scientist.

The observatory’s original function is to provide Canada’s primary longitude and determine and distribute time to Canada’s Parliament and other government offices.

Likewise, another more important task of the observatory scientists was to research on variations of gravity and its relation to the Earth and its mineral resources.

With a 38 centimeter refracting telescope as its primary astronomical telescope, the construction of the Dominion Observatory was finished in the year 1905.

The refracting telescope was acquired on April of 1905. Since then, this astronomical telescope became available to the viewing public every weekend. In 1974, it was transferred to the Canada Science and Technology Museum where it is presently being used.

Wednesday, August 16, 2006

Hook Your Kids to Astronomy

To belong to the field of astronomy must be very exciting and full of adventure. Often times I would imagine myself as a staff at NASA, perhaps a member of huge group of people that's responsible for sending manned spacecrafts into place.

Or perhaps an astro-scientist whose assignment is regularly checking out what the Hubble Space Telescope has been capturing via photo in space.

Well it might be late for some of us to make career changes. The next best thing is to see if our kids are as interested as we are in astronomy. And if so, try to encourage them further and helping them build a sure and clear path into this field.

Some common-knowledge advices on encouraging kids to involve themselves in Astronomy:

Bring them to planetarium and observatories where there are regular film showing on the planets and the sun and stars. Check observatories which allow their refracting telescope or reflecting telescope instruments to public use.

Tell them great stories about astronomers such as Galileo Galilei and Wilhelm Herschel and their exploits of the heavens, discoveries and contribution to the science of astronomy.

You can further to inspire your kids than to give them a telescope. A nice inexpensive refracting telescope will do. It is a simple instrument for the kids to very much understand and learn about its parts and their function.

It would be much better if you can build with your kids a simple refracting telescope. All you need are two lenses, which are the objective lense and the eyepice lense. Also you will be needing a long plastic tube that will hold the two lenses.

Building this refracting telescope with your kids will surely build up much interest in astronomy. Moreso when the refractor is done and they would get to enjoy great moments of stargazing.

Monday, August 14, 2006

Refracting Telescope and Chromatic Aberration

The refracting telescope is the earliest instrument used for serious astronomical study and has earned a very important place in the history of astronomy.

From the earliest Galileo telescope and the simple refractor telescope of Hans Lippershey, to the modern refractor – this device is by far one of the most prolific when it comes to astronomical discoveries.

It is also one of the simplest; anyone can build a refractor telescope following its basic principle. You can assemble a simple scope if you have in hand any long tube and two lenses, which would act as the eyepiece and objective lenses.

This is as opposed to the reflecting telescope. Instead of objective lens and eyepiece, basically mirrors for gathering and magnifying light are used by the reflecting telescope.

Indeed, the refractor is an efficient instrument used for viewing distant objects such as planets or even stars.

However, the refracting telescope is a flawed instrument.

Have you heard of chromatic aberration? It is an optic occurrence wherein different wavelengths of lights that pass through a lens are caused to likewise have different focal lengths. And since every color of the spectrum can’t be focused at a common point of the optical axis, the image is surrounded with colors.

This optical defect is minimized, if not corrected, by using achromatic optics or doublets. These achromats are equipped with materials that are bonded to form one lens. This in turn helps in minimizing the degree of chromatic aberration.

Many glass materials are being utilized in minimizing chromatic aberration. Glass containing fluorite are said to be the best in reducing this optical defect in refracting telescope.

Friday, August 11, 2006

Uppsala Astronomical Observatory

In Sweden is where you can find a popular astronomical observatory named Uppsala Astronomical Observatory. It goes back to the 1700’s when Ander Celsius, a professor of the astronomical sciences in Uppsala University, founded the observatory and made his astronomical researches and studies there. Most researches at the Uppsala involve galaxies, solar system and solar atmosphere.

The Uppsala Astronomical Observatory is under the supervision of the Uppsala University’s Department of Astronomy.

The astronomical telescope instruments of Uppsala Observatory

Refracting Telescope. This double refractor telescope was acquired by the Uppsala Observatory from the government through the efforts of Professor Nils Duner. The optical system of the refracting telescope were manufactured and built by the Steinheil from Munich in Germany while the refractor’s mechanics were built by Repsold.

The instruments were utilized mainly for purposes of research and astronomical studies, the most significant of which are those which involved the double stars.

The prolific refracting telescope has produced numerous spectral and photographic plates which are now included in the observatory’s rich archive.

Reflecting Telescope. A Westerlund Cassegrain telescope, it is found on the Angstrom Laboratory. This 90 centimeter reflecting telescope is now used for student researches as well as professional astronomical studies.

Wednesday, August 09, 2006

Carter Observatory

One of the most popular observatories in New Zealand, the Carter Observatory can be found in the area of the Botanical Garden in Wellington.

The Carter Observatory was founded and built thru the generosity of a New Zealand politician and wealthy farmer Charles Carter, hence the name.

The observatory became operational in the year 1941 and became a major institution of New Zealand for scientific and astronomical research. Housing a reflecting and refracting telescope instruments, it also promotes astronomical researches undertaken by non professional astronomers.

Presently the Carter Observatory is recognized by the title “The National Observatory of New Zealand.”

Carter’s Refracting Telescope

One of the main astronomical telescope instruments of the observatory. More popularly known as the Cooke refractor, this 9 ¾ inch refracting telescope is named in honor of Thomas Cooke, the famous maker of instruments.

This refractor is used mainly for public sky gazing and viewing.

Carter’s Reflecting Telescope

The Observatory also serves as the site for the Ruth Crisp Telescope, a 41 cm reflecting telescope which was purchased and acquired for astronomical use in 1968.

Zeiss Projector

Carter also operates and maintains a planetarium, which comprises a theatre, some shops, and a Zeiss Projector.

Monday, August 07, 2006

Allegheny Observatory

In the City of Allegheny of Pennsylvania, the Allegheny refracting telescope observatory as founded on the 15th of February, 1859. Situated in Riverview Park, the observatory is a part of the University of Pittsburgh. Consequently, the some residents of the city created an astronomy and telescope group, the Allegheny Telescope Association.

Presently, the Allegheny Observatory is recognized as one of the major telescope and research observatories in the world. Originally intended for general public use, the observatory’s refracting telescope and astronomical equipments are currently utilized for astronomical researches as well as for the science requirements of the University’s students.

The refractor telescope and reflecting telescope instruments

The Allegheny observatory has one reflecting telescope and two refracting telescope instruments in use.

Keeler Memorial Reflecting Telescope. Found on the second biggest dome, it was named in home of the observatory’s director, James Keeler. Built by Brashear Optical Company in 1906, the Keeler was known for its study and observations of the sun.

Fitz Clark Refracting Telescope. This 13 inch scope by built in 1861 by Henry Fitz. The second name “Clark” was added after a magnificent repair by Alvan Clark Company. Of the three scopes, the Fitz was the one primarily used for tour groups and star gazing activities.

Thaw refractor telescope. Donated by William Thaw Jr, it is located under the biggest dome of the observatory. Constructed in 1912 also by Brashear Optical Company. The main function of the Thaw scope was photographic – it is one of the most prolific in the world in terms of photographic plates.

Friday, August 04, 2006

McCormick Observatory

At the University of Virginia in Charlottesville, State of Virginia is where astronomy enthusiasts can find the McCormick refracting telescope Observatory.

The founder of this refractor telescope observatory is Leander J. McCormick, a wealthy businessman, manufacturer and philanthropist. McCormick donated his personal money which was used to purchase a refracting telescope for the observatory. He also financed the construction of the observatory itself.

The refractor telescope was the largest astronomical telescope in the United States at the time of its completion. It was built by the famous scope lens makers Alvan Clark and Sons.

It is quite similar to the refractor at the United States Naval Observatory as both are made by Alvan Clark and Sons. Albeit it is said that the scope of the McCormick is of better quality than that of the USNO.

Other facts about the McCormick refracting telescope observatory are the following:

It is a 26 inch (66.04 centimeter) refractor telescope.

The dome of the observatory is 45 feet and has a three shutter design, making it the largest not only in the States but worldwide.

Presently the McCormick refracting telescope observatory is being used for astronomical researches, lectures, sky gazing sessions and public viewing. Likewise weather, meteorological and atmospheric studies and observations are done and taken at the observatory.

Wednesday, August 02, 2006

Lippershey, Galileo, or della Porta?

Who deserves more recognition in the invention of the refracting telescope?

Many historians would be fast in giving credit to Galileo Galilei. Galilei’s Galileo Telescope was actually the first refractor that was used to study the stars and heavens seriously.

Galileo is actually recognized as the “Father of the modern refracting telescope.”

Others would contend that Hans Lippershey, a lens maker originally from Germany but later migrated to the Netherlands, was actually the inventor of the refracting telescope.

A popular story is that Lippershey’s children were playing and tinkering on two lenses. The children were delighted that the images of objects that they see through the lenses appear larger.

Lippershey noticed this, begun working around the mechanics and was build to build a crude refractor.

Another “inventor” of the refractor?

But did you know that many historians are considering a prominent academician from Naples, Italy, Giambattista della Porta, as the one who deserves the credit in the invention and development of the astronomical telescope in question?

Giambattista della Porta is a scholar and expert on many fields such as cryptology, and also has a wealth of knowledge on lenses and eyepieces. He made claims about being the one who invented the refractor, albeit he was not able to present the invented optical instrument to support his claim.

Friday, July 28, 2006

Buhl Planetarium and Its Telescope Observatory

Located in the northern side of Pittsburgh, the Buhl Planetarium or Buhl Science Center opened in 1939 and became a major planetarium and astronomy center in the United States.

Two years later its refracting telescope observatory became operational, and become known as the People’s Observatory, aptly named as it was dedicated to the public. Very much involved with the founding of the People’s Observatory was Harlow Shapley, a well known American scientist and astronomer of Harvard College Observatory, who dedicated it to the public in 1941. (The moon’s Shapley crater was named after him.)

The People’s Observatory featured its major refracting telescope instrument – the 25.4 centimeter (10 inch) Siderostate refractor telescope.

Actually before the 10 inch refracting telescope came to be used by the astronomical observatory, a 10.16 centimeter (4 inch) Zeiss scope was bought by Buhl. But it was apparent upon its use and checking of its specifications and astronomical and optical functions that they made the mistake of purchasing the Zeiss scope.

So the 25.4 centimeter refracting telescope immediately took over upon its acquisition albeit the Zeiss refractor is still being used at the Henry Buhl, Jr. Planetarium.

The planetarium also has an observatory dome where astronomical enthusiasts and find and use a Mead reflecting telescope.

Tuesday, July 25, 2006

Vatican Observatory and its Zeiss Refracting Telescope

The Vatican observatory is said to be one of the oldest astronomical telescope observatories in the world.

Before the Vatican observatory, the Papacy built three previous observatories, the Roman College Observatory, the Specula Vaticana, and Observatory of the Capital.

In 1891, this refracting telescope observatory was rebuilt – this time it was constructed on a hill near the St. Peter’s Basilica.

But because of the development and growing population of the City of Rome, its skies became too bright for astronomical studies making it less than ideal for the Vatican Observatory to stay there.

So the Vatican Observatory transferred at the Summer Residence of the Pope located in Castel Gandolfo which is southeast of Rome.

Still the continuing increase brightness of the Roman skies slowly but steadily affected the scientific and astronomical research of the observatory.

Because of this, the Observatory in 1981 built a second an astronomical research group, known as the Vatican Observatory Research Group (VORG), in Arizona, US. The research group is considered one of the best and modern in the world.

The Vatican refracting telescope observatory has one of its major refractor and astronomical telescopes the Zeiss refracting telescope. The Zeiss scope was mounted and made available on the 29th of September 1935.

The aperture of the Zeiss scope is 40 centimeters.

Other important specifications of the Zeiss refracting telescope is the Focal Length which as 600 centimeter and the Image scale which is 34 inches / mm.

Aside from the Zeiss scope, other astronomical telescopes and instruments at the observatory are the Double Astrograph, Schmidt and Lennon Telescopes.

Sunday, July 23, 2006

Refracting Telescope: One of the Greatest Astronomical Discoveries

The basic design, the function of the eyepiece and lens, and optical mechanics of a refracting telescope is so simple that even a middle school student would be able to enumerate its parts, lens and eyepiece – few as they are.

While it is a fact the refracting telescope is one of the simplest types of astronomical telescope – it contributes greatly in the science of astronomy being one of the more important and major instrument utilized in many innumerable astronomical discoveries.

It is unfortunate that the refractor is an imperfect instrument as it possesses a major technical flaw which is known as the chromatic aberration. Chromatic aberration is a defect in which all the lights that pass through the lens do not meet on one point of focus. This in turn renders the vividness and clarity of the images to become inferior.

Because of such defective feature of the refracting telescope, this astronomical telescope gradually became known as an ineffective type of telescope. The refractor acquired the image of being not very reliable for astronomical gazing, study and research.

The popularity of the refractor as a dependable astronomical and stargazing instrument continued to dwindle all the more especially with the invention of a more improved version of the reflecting telescope. Eventually, the reflecting telescope took over the refracting telescope as the important astronomical telescope of modern times.

The fact is, there is not a major refractor built and constructed in recent times.

But the honor can not be denied – the discovery of this astronomical telescope is indeed one of the most important events that helped greatly in the advancement of the science of astronomy.

Thursday, July 20, 2006

Crosby Ramsey Refracting Telescope Observatory

One of the smaller, more “personal” but popular like the world’s major refracting telescope observatories, the Crosby Ramsey Memorial telescope observatory can be found at the Maryland Science Center, right at its rooftop. Aside from the Observatory, the science center, located at the Inner Harbor, Maryland has exhibits including dinosaur displays which are open to the public. The Maryland Science Center continues to improve and grow and the latest addition to its modern facilities is a state of the art theater

The memorial observatory has as its scope centerpiece the computerized and improved 8 inch refracting telescope. The observatory bought this refractor from the famous optical lens manufacturing company Alvan Clark and Sons way back in 1927.

And because improvements are done on the Crosby Ramsey’s Alvan Clark refracting telescope – it now boasts of being able to provide and capture astronomical images aside from the usual near earth objects like the moon.

Computerization likewise makes stargazing a lot easier – the refracting telescope trains itself to whatever sky object an observer desires to view by the simple use of commands.

The Crosby Ramsey telescope observatory continues to improve and grow and the latest addition to its modern facilities is a state of the art theater.

The telescope observatory is committed in providing its services to the public, and is open to everyone on Thursdays and Sundays for its sun and star gazing activities.

Tuesday, July 18, 2006

Gifford Refracting Telescope Observatory

In New Zealand is a popular refracting telescope observatory named the Gifford Observatory. The Gifford observatory can be specifically found on Mount Victoria, in Wellington.

The refracting telescope observatory, which has become one of Wellington’s great pride when it comes to great contributions to the advancement and promotion of the science of astronomy and stargazing, was founded in 1912 by Charles Gifford who is a scientist, astronomer and college mathematics professor.

The astronomical telescope centerpiece of the observatory is the 130 mm Zeiss refracting telescope. Together with the scope were excellent astronomical instruments such as a photograph developing instrument, a spectroscope, and an astronomical camera or an astrograph.

The refractor is as popular as the Gifford observatory’s founder as both pictures of the Charles Gifford and the refractor are hanging on the observatory building’s wall.

Unfortunately, during the 1970’s the Gifford astronomical facility lost its former excellent condition and begun to deteriorate until it became not fit to operate.

In recent years however, after some time of undergoing renovation and restoration, the Gifford refracting telescope observatory finally becomes fully operational today and are being used mostly for the students of Wellington for group study sessions, as well as the local astronomical societies.

Saturday, July 15, 2006

Griffith Observatory and Its Refracting Telescope

The Griffith refracting telescope observatory was founded by Griffith J. Griffith, a millionaire from Los Angeles, California. The popular observatory can be found in the City of Los Angeles, on Griffith Park, Mount Hollywood. The location affords visitors magnificent sights of many places in California such as Los Angeles itself.

Griffith was inspired to built the observatory after he visited the Mount Wilson Observatory.

With construction money of 100,000 dollars from Griffith, he instructed the building of the observatory on Mount Hollywood. The mountain top observatory was finally open on 1935 with its facilities available to the public.

Later after his death, ownership and operation of the Griffith Observatory was turned over to the city of Los Angeles.

One of the more popular astronomical telescope at the Griffith Observatory was the 12 inch (1 foot) Zeiss refracting telescope.

Ever since the opening of the observatory, this refracting telescope became available to the public, mostly people of Los Angeles and California. It became the stargazing refractor for the general public.

It is even said that many celestrial and astronomical objects such as comets and asteroids were viewed through the Zeiss refractor than any other refracting telescope in the United States.

Thursday, July 13, 2006

Refracting Telescope of Dollond

Another astronomical telescope worth mentioning is the Dollond refracting telescope.

This refractor with glass and brass as the main materials was assembled and built by London optical instrument maker George Dollond in the year 1836 in England.

Some of the important optical specifications and qualities of the Dollond refracting telescope are:

This refractor’s focal length is 0.3 meters or 300 centimeters. Focal length is the length of the path from the lens to the eyepiece through which light passes.

Length and height are both measured at 18 centimeters.

The refractor’s aperture is measured at approximately 18 centimeters. The aperture is defined as the diameter of the primary mirror or lens of the telescope. The higher the value of the diameter of the mirror or lens, the more vivid and detailed with be the image.

The Dollonds – famous astronomical and refracting telescope builders

George Dollond was a famous European inventor, optician and eyepiece maker. His scientific inventions were important gadgets utilized not only in the field of astronomy, but also in navigation.

George Dollond, together with father John and uncle Peter, became very famous all over Europe as being great builders and inventors of astronomical telescope equipments, as well as reliable navigation gadgets, equipments and instruments.

Tuesday, July 11, 2006

On Refracting Telescope Lenses

The mechanics of a refracting telescope is easy enough to be understood even by non-enthusiasts.

Anyone with little skill can even build a simple refracting telescope. But of course, the most important parts of this astronomical telescope are its lenses.

As we already learned from my earlier post on this type of telescope, its two lenses are the objective lens and the eyepiece lens.

Once you have these two lenses, you are on your way to building your first astronomical telescope for your stargazing endeavors.

The objective lens is convex lens – the light gathering lens, and the larger of the two. This lens is found at the front end of the telescope tube.

The eyepiece lens, on the other hand, is on the opposite end of the tube and the one that magnifies the picture or image of the object.

Should anyone decide to assemble a refractor, it is best to go to a recognized scope dealer and manufacturer in your area for the best lenses.

A refracting telescope has been eclipsed by more modern astronomical telescope – this is due to the fact that this telescope delivers less than perfect images for astronomical enthusiasts to enjoy.

Nonetheless, many telescope novices choose the refractor when building their own scope. This is because of the fact that parts of the refracting telescope are few, simple and readily available.

Related Posts:
Refracting Telescope: Today's Modern Galileo Telescope
Refracting Telescope: On Brightness and Magnification

Friday, July 07, 2006

More on Hans Lippershey and His Refracting Telescope

The history and invention of the refracting telescope would not be complete without mentioning Hans Lippershey.

Lippershey is not only credited with the invention and construction of the first refracting telescope, but also of the world’s very first practical telescope.

In fact the Lippershey refractor was the sole model of the Galileo telescope – the first real astronomical telescope and a much more improved version of refracting telescope, in terms of mechanics and astronomical stargazing.

A Dutch optician and lens maker, Hans Lippershey was born in Germany but spent his life in Middelburg, Netherlands. Lippershey was experiencing success as a maker of spectacles, since he belong to a flourishing trade at that time.

Lens making became more established and exciting when new techniques on glass making were brought it from Italy.

There were contentions that the refracting telescope was not an idea original to Hans Lippershey but actually to his children, whom he observed one time playing and tinkering around with some lenses.

Still it is needless to say that Hans Lippershey should be given the same importance and credit many accord to Galileo Galilei when it comes to the invention and evolution of the refracting telescope.

Similar post: Refracting Telescope: Lippershey’s Invention

Wednesday, July 05, 2006

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Tuesday, July 04, 2006

Merz and Mahler Refracting Telescope: The Great Refractor

With the lens built by the German telescope building company Merz and Mahler, this 15 inch (or 1.25 feet) refracting telescope was constructed in the Harvard compound, in Cambridge, Massachusetts in 1847.

For two decades, the Merz and Mahler Refracting Telescope, which is more popularly known as the Great Refractor, was the largest astronomical telescope in the United States.

The Great Refractor was housed by the Harvard College Observatory, Harvard University’s center of research on astronomy.

During its time, the Harvard’s refracting telescope was popular for being instrumental in capturing and producing very vivid and detailed images of the moon. In fact, some of these images won recognition in the international photography exhibition at the London Crystal Palace.

Another important achievement was the eighth satellite and inner ring of Saturn, which was a feat of father and son W. Bond and George Bond.

Still another achievement was the daguerreotype of the star Vega.

Other important astronomical finds done with the 15 inch refracting telescope was the discovery of asteroids and other near earth objects.

Today, the Great Refractor is used mainly for observation purposes and students’ astronomical researches.

Saturday, July 01, 2006

Ralph A. Worley Astronomical Telescope Observatory

In Shreveport, State of Louisiana is where you can find the Ralph A. Worley astronomical telescope Observatory. The reflecting telescope and refracting telescope observatory was constructed in 1964 by a group of astronomy enthusiasts called the Shreveport-Bossier Astronomical Society, to be later donated for use by the Caddo School System.

Presently the reflecting telescope / refracting telescope observatory is used by the Louisiana State University at Shreveport (LSU-Shreveport) for their scientific and astronomy classes.

Likewise, astronomical groups and associations take advantage of this observatory in Shreveport – and many stargazing sessions, astronomical classes, meetings and programs, as well as astronomical lectures are being held at this Shreveport observatory.

The Ralph A. Worley Observatory is home to a Newtonian reflecting telescope (16 inches) and a 6 inches refracting telescope. The Worley Observatory has actually two telescope buildings – The dome type building houses the Newtonian reflecting telescope, while another building (this one has a leveled roofing) beside it contains the 6 inch refracting telescope.

The Ralph A. Worley is still available for various astronomical researches and stargazing, albeit currently it is in a stage of major upgrading and maintenance.

Tuesday, June 27, 2006

Royal Observatory's Refracting Telescope

I wish I could see personally the 28 inch refracting telescope of the Royal Observatory. Majestic and imposing is how I can describe this refracting telescope as I see it in some pictures. And royal too, like how the observatory that houses it is called.

If you would like to see this famous astronomical telescope, visit the Royal Observatory which is found in Greenwich, London. The Royal Observatory was built in 1675 by Christopher Wren, architect and astronomer, being commissioned by the Charles II. The observatory was created not only for astronomical purposes but also in aid of navigation.

The 28 inch astronomical telescope of the Royal Observatory is United Kingdom’s largest refracting telescope and one to the world’s largest.

This famous scope is also known to the astronomy world as the Great Equatorial telescope, was not the original astronomical telescope in the Royal Observatory, but was a much fitting replacement to the Merz astronomical telescope.

It was constructed in 1893, and was commissioned by Royal Observatory astronomer William Christie. 28-inch refracting telescope it was called because its objective lens is 28 inches in diameter. It is 28 feet in length and over a ton (approximately 1.4) in weight.

Sunday, June 25, 2006

Lowell Astronomical Telescope Observatory

In Flagstaff City, the state of Arizona you can find the Lowell astronomical telescope Observatory. Actually the Observatory has two operating locations in the city – with the main facility found on Mars Hill.

Mars Hill is where the 24 inches (or 60 centimeters) Clark Refracting Telescope is found.

The Clark Refracting Telescope was actually built in Massachusetts by Alvan Clark, well-known American astronomer, optician and builder of astronomical telescope, eyepieces and lenses, and responsible for building some of the most famous refracting telescope equipments in the United States.

The Clark refracting telescope is built in 1896 and presently available for public use.

The other Lowell observatory location is found in Anderson Mesa Station. While the Mars Hill houses a refracting telescope, the Lowell observatory Anderson Mesa station has some reliable reflecting telescope equipments:

The 72 inch Perkins reflecting telescope

The Lowell Observatory Near-Earth-Object Search Schmidt scope (astronomical telescope primarily for use on near earth astronomical objects)

The 42 inch John Hall reflecting telescope

And another 31 inch reflecting telescope (previously utilized for research by the USGS)

The Lowell telescope observatory has secured a place in astronomical history wherein its refracting telescope and reflecting telescope equipments played a major role in astronomical discoveries.

Presently Lowell observatory is undergoing construction of its largest scope, the Discovery Channel Scope, which will be operational few years from now.

Wednesday, June 21, 2006

Lick Observatory's Refracting Telescope

Lick Observatory is the first refracting telescope and astronomical telescope observatory built on a mountain site.

Lick astronomical telescope Observatory is located on the top of Mount Hamilton, along the Diablo Range of California. It is under the supervision of the University of California.

It is for this reason that the construction was never easy but instead was a difficult and challenging task. Roads to the top had to be built to provide for a way for the horse-drawn wagons to bring the refracting telescope and other astronomical telescope equipments and construction materials.

The refracting telescope of the Lick Observatory was 36 inches or over 91 centimeters. During the time of its creation, this astronomical telescope was the largest refracting telescope, until it was taken over upon the creation of the Yerkes telescope.

Aside from its 36-inch refracting telescope, Lick also maintains astronomical instruments and other astronomical telescope as well as reflecting telescope equipments like the 3-m and 1-m Shane reflecting telescope, Coude Auxiliary Telescope, 36 inch Crossley Reflecting telescope, dual astrograph, and the Katzman Auto Image Telescope.

The Lick Observatory was built by millionaire James Lick, upon the influence of George Davidson, an astronomer who convinced him that the refracting telescope observatory would be a great legacy.

Monday, June 19, 2006

USNO Refracting Telescope Observatory

The most recognized refracting telescope observatory – more popular then any other astronomical telescope and refracting telescope observatories in the United States and the world is that of the US Naval Observatory (USNO).

The US Naval Observatory is a very reliable authority in navigation and fundamental astronomy.

Thu US Naval Observatory is proud of its 26 inches (66 centimeters) refracting telescope. Students, visitors, tourists, stargazers can check on the astronomical telescope and facilities of the observatory as it is open to the public.

This famous astronomical telescope observatory was made and constructed by the firm Alvan Clark & Sons in 1873 and is originally located in the Foggy Bottom District of Washington DC. During that time, the astronomical telescope observatory was considered as having the world’s largest refracting telescope.

The owner of the firm, Alvan Clark, is a well-known astronomer and scientist. Aside from the refracting telescope of the US Naval Observatory, his telescope and lens making firm also ground lenses for the refracting telescope of the Yerkes Observatory, as well as that of the Lick Observatory.

Some of the more important scientific and astronomical achievements made with the USNO astronomical telescope observatory is the discovery by Asaph Hall, an American astronomer, of the planet Mars’ two moons in 1877, which were consequently named Phobos and Deimos.

Friday, June 16, 2006

Kirkwood Refracting Telescope Observatory

The Kirkwood Refracting Telescope Observatory, which is located with the campus are of the Indiana University (IU) in Indianapolis is one of the many refracting telescope and astronomical telescope observatories found in the United States.

The most well known astronomical telescope of the Kirkwood Astronomical Observatory is the 12 inch (1 foot or .3 meter) refracting telescope.

Constructed in year 1900, the Kirkwood Refracting Telescope Observatory was named in honor of Daniel Kirkwood, a professor of mathematics at the Indiana University. Daniel Kirkwood is also an astronomer – he was the discoverer of the division or gaps found within the asteroid belt in our solar system called the Kirkwood Gaps.

Albeit the refracting telescope observatory is not open and available to the public the whole time of the year (it is open only on school months), when operational it is usually open to the public every Wednesday evening on a clear weather. The admission is free, and there is no need for prior reservations.

The refracting telescope of the observatory is used by the university’s college students for their astronomy and sciences course. In fact, the Kirkwood observatory is more known as a student observatory – primarily catering to students, especially that of the Indiana University. Other astronomical telescope of the observatory is the solar telescope, which is used by the astronomy students for studying the sun, its features, as well as the solar phenomena like the solar eclipse.

Sunday, June 11, 2006

Yerkes Observatory's Refracting Telescope

Do you know where the Yerkes refracting telescope is? One of the largest refracting telescopes in the world, if not the largest (another large astronomical telescope – refractor is the Mount Wilson’s refracting telescope), it was built in 1897 by the Massachusetts astronomer, scientist and master optician Alvan Graham Clark. Clark’s family was engaged in producing astronomical telescopes and lenses – this definitely influenced Clark to be serious in his astronomical pursuits.

The university based astronomical observatory has the world famous refracting telescope as its centerpiece among its astronomical telescopes - two of which are the 41 inches and 24 inch reflecting telescopes. The Yerkes refracting telescope itself has a 40 inch lens and a focal length of 20 meters.

The University of Chicago in Williams Bay at Wisconsin is the proud location of the Yerkes observatory. Built in 1897 by famous astronomer George Ellery Hale, the observatory was funded by Charles Tyson Yerkes, a transport tycoon and financier from Chicago, hence the name of the observatory. Hale was instrumental in convincing Yerkes to finance the building of the observatory, pointing out the nobility of its purpose. And indeed, Charles Tyson Yerkes was convinced to involve himself in this ambitious project, but strongly insisted that the refracting telescope to be built should be the largest in the world.

Today, the Yerkes observatory provides access to its facilities – the refracting telescope as well as the other astronomical telescopes - for scientific and stargazing researches and pursuits.

Tuesday, June 06, 2006

Refracting Telescope: On Brightness and Magnification

So you want to build a telescope just like how Galileo Galilei built his version of the refracting telescopethe Galileo Telescope.

If you are an astronomical newbie who wishes to start on the hobby not by buy an astronomical telescope but instead want to build a telescope – a refracting telescope – go ahead. The mechanics of building a refracting telescope are simple enough for someone with little knowledge about telescope to comprehend.

Likewise, if you are a dedicated and knowledgeable astronomy enthusiast – the refracting telescope is also an excellent stargazing instrument of choice. The refracting telescope can offer you vivid and crisp images of the moon, the planets and other sky objects within our Solar System.

In building your own “Galileo telescope”, you must realize not important fact – magnification of sky objects is not that all important!

What is magnification? It means enlarging sky objects such as the planets and stars in order for us to see and enjoy such objects’ more detailed features. The problem however is that many of these objects are so distant that magnification becomes useless. Even if we try enlarging the images, it is impossible for such images to come clear and vivid to us.

Which makes sense for you to try and get a larger objective lens for your refracting telescope. Larger objective lens means brighter, and hence more vivid sky objects to enjoy.

So in building a refracting telescope (your version of Galileo Telescope), you should put weight more on the brightness that your objective lens will bring to the images, rather than the magnification.

Saturday, June 03, 2006

Refracting Telescope: Today's Modern Galileo Telescope

Ever since the Galileo Telescope, as a refracting telescope, evolved to the modern optical instrument as it is today, more and more are using it as their choice for their astronomical and stargazing activities.

Galileo telescope was not the first refracting telescope. We all know all that Hans Lippershey build the first. Nonetheless, it was the first optical instrument to be used for serious astronomical and stargazing purposes. More or less, this type of astronomical telescope works on a similar concept as how the microscope does.

The monocular is a lightweight type of refracting telescope. Its bulk is half that of the binocular, and works by enlarging the object by letting light go through a couple of lenses as well as prisms.

Parts of refracting telescope

1. Hard Plastic or metal tube - this part of the telescope holds the scope lenses

2. Objective or convex glass lens located at the front of the tube – so-called because it is the lens closer to the particular object being viewed. This type of lens refracts the light it gathers, and focuses it at a point to the rear end of the tube. Objective lenses have longer focal lengths than the eyepieces. Focal length means the measure of how strong a lens focuses light. Long focal length means higher magnification power.

3. Eye Lens or Eyepiece - the lens nearer to the eye. Likewise a convex lens, it brings and magnifies the images to your eye.

Advantages of refracting telescope

1. Despite its tube length, it is easy to set-up and requires minimum maintenance

2. You would want to use a refracting telescope which is perfect for viewing the moons or the planets

3. Objective lens is fixed permanently to the telescope, thereby minimizing optical damage.

Disadvantages of refracting telescope

1. One major disadvantage: Because the lens bends the light it gathers, the result of the image is not very clear.

2. Because its aperture or hole through which light passes through is limited, it makes this telescope less capable of clearly viewing distant astronomical objects.

3. Its tube is longer, hence heavier than the reflecting telescope or Newtonian telescope.

Thanks to Galileo Galilei and his Galileo telescope, its evolution which is the refracting telescope of today has become one of the more reliable optical instruments for astronomical endeavors.

Wednesday, May 31, 2006

Refracting Telescope: Hans Lippershey's Invention

The Galileo telescope, which is a refracting telescope, is not the first scope to be invented. As everybody knows, from the stargazing newbie to the high school science geek to the serious astronomer – Galileo Galilei did not invent the telescope. Nonetheless, Galileo's telescope was a better and much improved version of the Dutch-invented refracting telescope.

And although he was not credited for the scope’s invention, he nonetheless provided a serious approach to astronomy and stargazing with his own invention. Galileo actually is the major contributor to the development and advancement of modern astronomy.

The inventor of the first scope was the Dutch lens maker Hans Lippershey in 1608. And I believe he deserves the credit, otherwise Galileo Galilei would not have a model from which he can pattern his own refracting telescope. He was a native of Germany who migrated to the Netherlands. He applied a patent for his invention but did not receive it. However for his efforts, he was generously compensated by the Dutch government in exchange for the copies of the designs of his invention.

Actually, Hans Lippershey’s refracting telescope is a simpler, much cruder than the Galileo telescope. Lippershey’s is made out of two lenses, the eye lens and the primary lens. In his application for patent, he intended his newly invented refracting telescope to be utilized for military purposes.

In honor of Hans Lippershey’s contribution to the science of astronomy, a crater of our moon was named after him (Lippershey crater).

Still the Galileo telescope is one major achievement which helped Galileo Galilei earn the title Father of the modern astronomy.

Wednesday, May 24, 2006

Reflecting telescope: Newtonian Telescope

Scientist Sir Isaac Newton (1643 - 1727) of Great Britain invented his own version of the telescope, which is a kind of reflecting telescope. This telescope of Newton utilizes two mirrors, one of which is parabolic in shape while the second is diagonal.

The parabolic mirror reflects an image to the diagonal second mirror. The image is then reflected by the diagonal mirror to an eyepiece which is mounted to the side near the top of the telescope tube. Newton’s use of the mirrors to focus light instead of lenses solved the problem of chromatic aberration. Chromatic aberration is the effect that occurs when light goes through a lens and colors were focused on different places, the result of which would be colors around the image.

The Newtonian telescope has one disadvantage – it suffers from instances of coma. Coma is an aberration that is off-axis in nature, meaning images flare away from the axis of the optics. Today, if your amateur telescope is Newtonian and you need to correct the coma – there are available lenses to bring back clarity and vividness of images. Check knowledgeable scope dealers in your area.

The Newtonian telescope is the simplest of all reflecting telescopes. Newtonians are indeed ideal as amateur telescope for stargazing newbies because it is relatively inexpensive, but still a very effective tool for astronomical endeavors.

The Newtonian is so simple that it is quite easy for amateurs to build a telescope of this type. Even the mirrors, especially the primary, can be built with quality by hobbyists.

Thursday, May 18, 2006

Refracting Telescope, Newtonian Telescope and Schmidt Cassegrain Telescope: The Differences

Let us enumerate the differences between the Refracting telescope, Newtonian telescope and Schmidt Cassegrain Telescope. Hopefully this will help astronomical and stargazing newbies to decide what kind of amateur telescope they would like to have.

Refracting Telescope

Galileo’s version of his telescope is a refracting telescope – and it was during its invention that astronomical pursuits are put to a higher level.

The refracting telescope's lens is convex, meaning it is thicker in the middle than its edges. It is for this reason that the light which passes through the edges are more bent than in the middle, with the lens gathering all the light to go to a focal point – the point where the image is formed.

One disadvantage of refracting telescopes is what we called chromatic aberration – which basically means the all light that go through don’t focus on a single point, making the image blurred. A specialized lens can be used to counteract the effect of chromatic aberration and make the images more vivid.

Newtonian Telescope

Named after its inventor Sir Isaac Newton. If you are a newbie in need of an amateur telescope – this is the best telescope for you. As a beginner telescope, the Newtonian is quite cheap but still very effective. It has a parabolic mirror that focuses an image to a diagonal. This diagonal sends the image to an eyepiece on top of the telescope tube.

One disadvantage of Newtonian telescope is what we call Coma, an aberration in which the image is set off the optical axis. You are experiencing this defect if the stars you are observing are having tails like that of comets, either flaring away from the axis or pointing toward it.

The Newtonian is the simplest of all reflecting telescopes.

Schmidt Cassegrain Telescope

An invention by German scientist and astronomer Bernhard Schmidt and French Cassegrain.

Schmidt Cassegrain is a combination of the refracting telescope and reflecting telescope, extracting the best qualities of the two. Schmidt Cassegrain is currently a favorite instrument for astronomic photography.

This telescope has a corrector that is intended to minimize if not eliminate spherical aberration. It also has primary and secondary mirrors – with the primary mirror having a hole through which the light reflected by the secondary mirror passes.

Aside from an excellent telescope for astrophotography, the Schmidt Cassegrain telescope is one of the most popular among amateur astronomers.

Thursday, May 11, 2006

Advice Before You Buy Telescope

If you are a stargazing hobbyist, a science student, or a someone who's in a serious career as an astronomer, you definitely would be particular with the instrument of the trade (or science for that matter) - your telescope.

You want your beginner telescope to be the best telescope, whether it's reflecting or refracting, or a space telescope. You want the best high-quality lens or mirror for excellent light gathering and resolution which in turn will provide you with magnificent views. You want your telescope to be very easy to set-up and have a reliable telescope mount for every possible movements.

If you want these qualities for a telescope, I have to go to a reliable and knowledgeable telescope dealer who knows the best unit that will suit your astronomy and stargazing requirements. Remember, never go to a discount store or a department store when you decide to buy telescope.

Now, before you buy telescope - the budget is one of the major considerations.

If you're into stargazing and astronomy seriously and you think that it is going to be a lifelong commitment, then it is best that you make a good investment. If you decide in buying an expensive telescope but with all the best specifications put in - it is best to consult your telescope dealer.

It's simply a wise investment to spend a little more cash for an A-1 telescope and enjoy your hobby to the fullest as possible.

Scope City is one of the telescope dealers that you may want to ask information regarding which beginning telescope is appropriate for your need.

Remember, never buy telescope from the discount or department store.

Don't scrimp on an endeavor or hobby that you would like to put your heart into and excel in.

Who knows, you may just be able to accomplish the next best astronomical discovery - all because of your excellent beginner telescope.

Have a great stargazing!

Related Post: On Buying a Starter Telescope

Tuesday, May 09, 2006

Building a Telescope

When you have decided that you want to start a stargazing hobby, the first thing that comes to mind is – where to I get my telescope. But with a limited budget to buy a beginner telescope, how can you acquire that one important gadget? Checking out the magnificence of the heavens cannot be without a scope in hand.

You have two options. Either you a buy a telescope. Or take the adventure of building telescope.

Then you finally thought: indeed, why not build your own telescope! A simple amateur telescope for yourself. A simple one would be that with no frills and unnecessary accessories. Just a basic but amateur telescope that is working fine. Definitely that would be more okay and agreeable to your limited budget.

How do you go about building telescope? Almost anyone can! You can build your own even if you are a total first timer in this hobby of stargazing. And with no prior experience in assembling.

Yes, you can build your own telescope even without seeing or using one in your whole life!

You can build an 8 or 10-inch Newtonian or a 4-inch Dobsonian scope. Whatever it is you want, it’s just easy to build your first beginner telescope.

Here is one resource that is very helpful to get you started in your quest to build your own telescope. Just remember to follow instructions properly and use the appropriate materials and telescope components. Consult and buy telescope components to the reliable dealers and retailers in your area.

Now with your beginner telescope, you can see heavenly objects more than when with just your naked eyes. You can now observe objects that are farther and fainter. Mars or Jupiter. Or even Jupiter’s moon. Pluto. Maybe another galaxy. Or a quasar perhaps.

So, with the resourses on hand, building telescope is quite easy. I know you can hardly wait to gaze up the heavens with your very own amateur telescope. Good luck with your scope-building!

Sunday, May 07, 2006

Telescope Mount

Many of you must already have your amateur telescope or astronomical telescope. Some must have plans to buy telescope, whether be it a simple beginner telescope or the best telescope there is.

One important advice before you buy telescope: seriously take into consideration the mount of your telescope.

Telescope mounts are an important part, mainly because mounts provide stability to the telescope, preventing the telescope from wobbling.

Whether you have an amateur telescope or the most professional telescope in use, you must see to it that it has a stable and reliable mount in order for your telescope to work at its best.

You also must do adjustments and movements to your telescope if you want to gaze at objects at different sections of the heavens. Such adjustments and movements on the telescope should be done without you worrying that it may fall or topple from its position.

A Mount is indeed necessary as a support to your telescope. Mount steady it up and keep it firmly in place.

Now that we have reiterated the importance of telescope mounts, let us discuss the two types of mounts:

Altazimuth Mount

1. The simplest, easiest-to-use mount.

2. The compatible mount to the Dobsonian Telescope.

3. With the Altazimuth, your telescope can be moved up and down (such movement is called altitude), and left and right ( called azimuth), hence its name.

4. It is a reliable mount, quick and easy to set up, and very firm and stable.

Equatorial Mount

1. This is the type of mount that has its axis pointed toward the North Celestial Pole.

2. The primary purpose of the Equitorial Mount is to track or match the movement of the stars.

3. This mount is perfect for long exposure photography because your telescope with move along with your target object.

4. Just make sure you acquire an excellent motor for your axis to make the most of your astrophotography session.

Equitorial mount comes in varieties -

Fork Mount: motorized mount that is best for short tube catadioptric scopes.

German mount: used for refracting scopes due to their lengthy tubes.

Goto mounts: (also Goto telescopes) has motors on all axes, and are so-called because they can be “commanded to go to” a celestial object.

Whatever may be the mount that you are using, make sure that is compatible with your amateur telescope or astronomical telescope to achieve the fullest stability for your telescope. Surely, with this taken care of, you will enjoy a wonderful stargazing!