Star Gazing Guide » Telescope Buying Tips

What Your Telescope Can Do

admin — Tue, 14 Jul 2009 02:01:29 +0000

The reason you bought a telescope is to view the night sky in all its glory. Telescopes can bring those objects closer and give you an idea of what is out there in th universe. Some of the objects you may see are the moon, planets, and the sun. With a little practice, you may be able to spot some comets, stars, nebulae, and maybe even other galaxies.

The Moon is the best object to view at first because of its prominence and brightness in the night sky. You can follow its phases and get a different view ever night. You might see its mountains, craters, or its terminator line. This is the line between light and dark where you can see a big contrast everywhere.

The Sun is one of the few objects in the sky that you can actually observe in the daytime. A word of warning here NEVER look directly at the sun through a telescope lens. The light can cook your retinas in seconds. ALWAYS make sure you have the proper solar filter on the telescope before you gaze at the sun.

Beginning astronomers like to count the sunspots. If you start sketching the spots and where they are each day, you will begin to see the pattern of the sun’s rotation. Another fun thing to do is watch during a solar eclipse when the moon passes between the earth and sun. This is the only time you will get to see the sun’s corona.

Viewing planets requires a dry atmosphere and good seeing conditions. Jupiter is the largest planet in the system, so you should be able to find it easily. Mars is difficult to focus on because of its small size. Venus is the brightest planet and also easy to spot. Saturn is always a neat planet because of the rings that change their angle as the planet orbits the sun. Unfortunately, Neptune, Uranus, and Pluto are very hard to locate and may only appear as tiny discs.

Viewing the Night Sky with a Telescope

admin — Tue, 14 Jul 2009 01:54:37 +0000

Depending on the type of telescope you have purchased, you should be able to see many wondrous images with it. You might see the moon’s surface, the moons of Jupiter, or even Saturn’s rings. With some knowledge of the sky and constellations, you may be able to pick out some star clusters.

The best way to get your hobby going is to join your local astronomical society. They will sometimes have telescopes you can borrow to get the hang of using one before you buy. They also meet in the evenings so you can learn how to observe the night sky. It is truly fascinating to see the images with your own eyes instead of just looking at pictures on the web or in books.

Telescopes are used for two reasons. One is to see fainter objects and the other is to magnify images far away. You must discern which focal ratio is the best for what you are trying to see. A focal ratio is the ratio of the focal length to the aperture. Usually starting around f/8 is good for beginners. Going below f/8 will give you wider, brighter views, but image quality will be lower. Going above f/8 is usually saved for viewing the moon and planets and deep sky objects such as galaxies or nebulae.

To get started, just set up your telescope and start looking into the night sky. There is no telling what you might see. You can look at the moon every night for a year and still not see everything it has to offer. The same is true for the entire Milky Way galaxy. There really is no limit to what you can find. Another neat thing to do is to count sunspots which provide a gauge of solar activity. Be sure to have the proper filter. Just have fun and see what you can find.

Viewing Deep Sky Objects and Comets

admin — Tue, 14 Jul 2009 01:46:11 +0000

Deep sky objects are usually located outside our solar system. The listing includes star clusters, nebulae, galaxies, and multiple stars. There is also a list of 110 objects on Messier’s list that you can try to locate. The key to viewing all these heavenly bodies is to go outside on a really dark night and you must have a large telescope (one which an aperture that is greater than six inches). Light pollution filters may also help improve your view.

What looks like one star in the sky actually becomes two or three when looking through your telescope. There is a four part star in Orion’s Nebula. There are also stars that brighten and dim as you watch them over time. These are called Variable Stars.
Star clusters are thousands of stars grouped together. They create a spectacular view when looking through a small telescope. An example of this is the Pleiades. This is a group of seven bright stars in the Taurus constellation that can be seen with the naked eye. But once you view them through the telescope, you will find there are thousands of stars in the cluster.

Large gas and dust clouds in space are called Nebulae. An emission nebula will produce light where a dark nebula will absorb the light. They can be a challenge to find.
Galaxies have massive numbers of stars that are held together by gravity and are usually found in clusters. They come in many shapes and sizes spiral, barred, elliptical, and sometimes irregular shaped. They appear as faint, fuzzy patches of dust.
Comets are fascinating to watch as they travel across the sky. They develop tails and can change brightness as they get closer to the sun. Not all comets will look the same either. They may brighten or darken depending on where in the sky you locate them.

Using a Telescope

admin — Tue, 14 Jul 2009 01:36:44 +0000

So you have gone out and bought a telescope and have no idea what to do with it. Go out into the night sky and look for the brightest objects you can find. They are the best to start with because they are easy to find. Then after that, the sky, quite literally, is the limit.
With a special filter, you can see the sun and count sunspots. Observe the milky way or the moon. The moon has many large craters and you may see rays coming out from them. These are from when a crushed rock exploded from meteor impact. Streaks are formed in a radial pattern out from the crater itself.
Jupiter can be quite interesting to observe at night. It is one of the most easiest to find besides the sun and moon. Some small telescopes might even get a good picture of Jupiter’s small satellite moons. They are usually in a straight line and appear as very bright stars. Given Jupiter’s rapid rotation, you can view nearly all the planet in a single night.
The simplest thing you can do is look at the stars. Sometimes, you may see a double-star. What looks like a single star becomes two when using a telescope. These are quite popular because of the explosion of color you will find between the two of them.
Charles Messier was a comet hunter. One day, he noticed some fuzzy objects that didn’t appear to be moving. These were actually the nebulae of today. Some people think it is fun to take a single night and see how many deep sky objects you can find on Messier’s list in a single night. There are 110 you can find.
The important thing is to have fun and spot the brightest stars first and go from there. This can be a rewarding hobby after you have had time to get used to the telescope and what it can do.

The Hubble Telescope

admin — Tue, 14 Jul 2009 01:30:32 +0000

Conceptualized in 1946 and launched in 1990, the Hubble telescope orbits the Earth and sends pictures back that aren’t blurred by background light or the atmosphere. The telescope was named after Edwin Hubble who made a great scientific breakthrough when he found that the universe was expanding. After the Hubble was launched into space, one of the main mirrors was causing aberrations in the pictures being sent back to Earth. In 1993, a servicing mission was deemed necessary and they returned the telescope to its former capabilities.
Currently in 2007, several of the Hubble’s turning gyroscopes have failed, and its main camera stopped working. There is a planned service mission scheduled for 2008 which will hopefully allow the telescope to function until 2013. After that, a new telescope will be launched to take its place. The James Webb Space Telescope will be superior to the Hubble in many ways, but will only record in infrared.
Challenges were also part of the telescope’s creation. It would have to able to withstand direct passes by the sun and behind the earth. Temperatures in these areas were either extremely hot or extremely cold. The scientists finally came up with a multi-layer shroud to keep the temperature within the telescope stable at all times.
The mirrors were another problem. They were polished and grinded from the beginning of 1979 until May of 1981. Using low expansion glass, they kept the mirror’s weight at a minimum. The mirror was finished by the end of 1981, and they added a reflective coat of Aluminum and a protective coat of Magnesium Fluoride.
The Hubble has given us pictures of comets, the planets, established the presence of black holes, and other stars and galaxies nearby. To view the wondrous images, go to http://archive.stsci.edu/hst and click on gallery. You will find some of the most incredible pictures you have ever seen.

The Best Telescopes Out There

admin — Tue, 14 Jul 2009 01:24:48 +0000

This will be a big surprise. Can you tell me what the best telescope out there today is? There are actually two of them. If you said your eyes, you are correct.
You were born gifted with two telescopes that can focus from one inch to infinity and beyond. They have a field of view of about 110 degrees, and they have built in lens covers. They open and close at about 1/40 of a second. Eyes can detect subtle color changes as well as any variance in color. They also send three dimensional depth information to your brain. No telescope could ever do all these things.
Go out before you start with the telescope and look at where you will be pointing it. Pick out several constellations by sight and look for the moon and a planet. Make a mental picture so you know where t go to come back to the object when you want to. Just relax and go out in the warm night air and look up. It really is that simple.
To get the most from learning astronomy, you must have a lot of patience. You may go several nights without seeing anything new. This is what frustrates beginners. Start with the moon and look at its brightness. Look for craters and mountains. There is so much to the moon that you could find something new every night for the next year.
Don’t give up though. Even though you didn’t find what you were looking for doesn’t mean it’s not out there. It just means you haven’t been able t see it yet. Keep looking each night. You may find something else you weren’t looking for and that will lead to other new objects as well. Look around star clusters and the planets. You may even spot some comets or meteors.

Telescope Mounts

admin — Tue, 14 Jul 2009 01:18:15 +0000

Mounts for telescopes are used for several different reasons. You don’t have to hold the scope yourself while you are trying to focus on an object. It helps to steady the scope. It frees you hands up so you can make sketches of what you are viewing or adjust the scope for better focus.
There are two types of telescope mounts you can employ for better viewing. One is the Alt-Azimuth. This mount is similar to a camera tripod. It uses the vertical (altitude) axis and a horizontal (azimuth) axis to help you locate your object. This type of telescope mount has two variations. The Ball and Socket which has a ball shaped end that can move freely. The second type is called a Rocker Box. This is usually made of plywood and has a low center of gravity. It has a horizontal circular base and Teflon ball bearings for the altitude axis. These are great mounts for a heavier telescope.
The second type of telescope mount is called the Equatorial. This mount uses two axes that are lined up with the poles to keep track of the motion an object takes across the sky. The axes can be Right Ascension, Polar, or Declination. Instead of moving up and down on its axes like the Alt-Azimuth, this particular mount is tilted toward the Earth’s axis of rotation. There are two varieties of this particular mount. One is the German Equatorial Mount. This mount is shaped like a T. The longer axis of the T is lined up with the pole of the Earth. The second variety is the Fork Mount. This is amount that is aligned with the Earth’s pole but is like a two-pronged fork that sits on a wedge. The prongs are one axis and the base of the fork is the other. You can use the Equatorial Mounts for taking pictures of the objects you find.

Telescope Advice for Beginners

admin — Tue, 14 Jul 2009 01:09:28 +0000

You have taken the plunge and purchased a telescope. Now what do you do with it? Astronomy can be a wonderful hobby, but here are some tips to make sure you get started on the right foot, or star as the case may be.
Look up the night sky without the aid of a telescope. Can you spot and name any constellations? Can you spot the moon or the planet Venus or Jupiter? If you can’t do this, you might have some trouble spotting other heavenly objects.
There are many magazines out there that follow astronomy and can give you sample pictures and sky charts to go buy. The most common are SKY, TELESCOPE, or ASTRONOMY.
Join an astronomy group or a star watching society. These groups usually have telescopes you can borrow for a look to see if it is really what you want. They also have advanced members who can teach you where to look for certain objects.
As any experienced astronomer will tell you, a pair of good binoculars can become your first telescope. They are relatively affordable, and if you decide astronomy isn’t for you, there are a dozen other uses for the binoculars. If you get a good pair the first time, you may not have to buy anymore, they last for a lifetime.
The biggest telescope is not always the best. Most amateurs like to use the six inch Dobsonian reflector type telescope. It is cheap, simple to use, and you can learn a lot from it before you move on. Instead of having to play around with controls, you will spend most of your time trying to aim and focus with this telescope. A six to eight inch aperture is large enough to view bright images of heavenly objects.

Smaller Telescopes

admin — Tue, 14 Jul 2009 01:00:47 +0000

Smaller telescopes are called refracting telescopes. They have a big lens at the front and an eyepiece in the back. Some say they are useless for astronomy, but it is possible to do some viewing with these special telescopes.
A telescope also needs certain features in order for it to be helpful in viewing objects. One is it must have a well-aligned and intact mirror. It must have at least one eyepiece, two are better. The scope must have a mount that firm and secure. Unstable mountings is a problem for beginner astronomers. You should also have a finder that rides beside the main telescope. It makes your field of view wider and makes it easier to find objects.
The first thing you should look for is the moon. You probably won’t need to use the finder as the moon is so big and bright. However, you may need to move the telescope every few minutes to keep the moon in view due t the earth’s rotation. You should find many craters and brights spots where the sunlight covers one side of the moon.
Small telescopes are great for viewing the planets. The rings of Saturn, the phases of Venus, and the moons of Jupiter are a few of the spectacular images you might happen across. You must use a lower power setting because higher power makes your images dim. Usually 80-120x is good to start out.
Deep sky objects such as nebulae, galaxies, and star clusters will be faint when compared to the planets. The brighter the deep sky object, the better you will see it. You can certainly observe these when you find them.
Small telescope are inexpensive. You can still learn a lot about them and the universe in the process. Take yours and see what you can find in the night sky.

Refracting Telescopes

admin — Tue, 14 Jul 2009 00:54:41 +0000

While we have no physical evidence, we have very strong documentation that refracting telescopes were used in England as early as the sixteenth century. The use of telescopes became widespread in the early seventeenth century in the Netherlands.
Hans Lippershey and Zacharias Janssen of the Netherlands claim the invention of the original telescope. This original scope had both concave and convex lenses so that the image would not be inverted. After the Netherlands started producing them, they were rapidly found all over Europe.
In 1609, Galileo was visiting Venice and claims to have solved the problems with the telescope by using a convex lens in one end and a concave in the other end. Thus, moving the two pieces of glass further away from each other. This led to better image viewing with less rainbow effects around the distant object. Galileo spent much of his time to perfecting the telescope after that. His first telescope magnified at a power of three diameters, and the best one he made magnified at a diameter of thirty-three diameters. These last telescopes were so great that in 1610, he discovered the satellites of Jupiter, the spots on the sun, and the hills and valleys on the moon.
These telescopes are common today. They are made out of a long tube of metal or wood. They have a glass lens at the front and back ends as well as an eyepiece at the back. The tube helps to keep moisture and dust away from the lenses for a better image. The two lenses help focus light and refract it to the back of the tube where the eyepiece magnifies it so that you can see it clearly.
Refracting scopes have a resolution high enough to see details in binary stars and planets. They are expensive and less useful for looking at other galaxies or nebulae. You can see a plethora of stars and other heavenly bodies with them though.