About Astronomy - Amateur Astronomy and Telescopes

Welcome!
If you're developing an interest in stargazing, getting into amateur astronomy, or even just buying your 10-year-old child a telescope, you're in luck. This website is dedicated to teaching you how to get started.

Beginning Steps

Before you jump into getting a telescope or even a pair of binoculars, buy a few good books about amateur astronomy. Nightwatch by Terence Dickinson and Turn Left at Orion by Consolmango and Davis are great books for beginners. While Nightwatch is a guide to observing, Turn Left at Orion is a catalogue of objects to observe.

You'll also want to pick up a Planisphere and a Star Chart. Go outside on a clear night every now and then and try to learn the constellations. Once you feel you've had enough practice, it's time to get a pair of good binoculars.

Binoculars: Before You Get A Telescope!

It is reccomended to get a pair of astronomy binoculars before you get a telescope. Why? Because binoculars give you low power, wide field of views of the sky which enable you learn the sky better.

Don't get binoculars with straight barrels (Binoculars with Roof Prisms), get the ones with barrels that are smaller in the back and wider in the front (Binoculars with Porro Prisms). The reason why is because Binoculars with Porro Prisms allow for more light to pass through. Also, for better light transmission and highly reduced glare, try to get multi-coated to even fully multi-coated binoculars.

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A good size of binoculars for beginners would be 7x50s, or maybe a little bit bigger. They're powerful enough to give you great views of Deep Space Objects, yet light enough to use without a tripod. When someone says their binoculars are "7x50's", that means that the magnification is 7, and their barrel aperture at the front is 50mm. Another important characteristic of binoculars to know are the eyepiece's exit pupils, or the width of the part of the eyepiece in which the light enters your eye.Now, about exit pupils: To find the size of the exit pupil of the binocular's eyepieces, divide the barrel diameter by the magnification. The average person above 40 years old has pupils which dilate to about 4.5 millimeters. Below 40, about 5-5.5 millimeters. Some teenagers and kids' pupils can dilate to even 6 millimeters! Why is this significant? It's important to have binoculars that have exit pupils which match the size of your pupils. Now you don't have to get binoculars the exact size of your pupils, you're just recommended to do that. It makes observing much easier on the eyes.

Once you feel you know the sky, get a telescope. For info on telescopes, go to the "Telescopes" link.

Observing

The Moon

Observing the Moon is a great way to get started. However, the Moon is an annoying distraction at times. As the Moon gets brighter, the stars get dimmer. This makes it harder to locate Deep Space Objects, along with other faint objects. Also, because of the brightness of the Moon, a Moon filter will normally need to be used during some of the larger Moon phases. Otherwise, your eyes will no longer be dark-adapted.

A Moon chart is a helpful tool for identifying parts of the Moon. You can purchase these online or at most large book stores. As the name says, a Moon Chart is a chart of the Moon and its surface features. A fun aspect of lunar observation is trying to identify the craters, mare, and mountains on the Moon.

The Planets

Not all of the planets are easy to observe. Mercury is too close to the sun, Venus has highly reflective clouds, causing it to look like a bright yellow blob, and Uranus, Neptune, and Pluto are too far away to be clear through most amateur telescopes.

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Now Mars, Jupiter, and Saturn and big exceptions. Through an 8" reflector , a good starter telescope, Mars shows ice caps (When Mars is closest to Earth, at least). I must admit, though, Mars is a very disappointing planet. You expect it to be big, showing red and brown sands and clouds, but it won't look like that at all through an 8" reflector. On the other hand, Jupiter and Saturn are MUCH bigger than you probably would expect. Jupiter shows four of its moons, tan and red cloud bands, and even the Great Red Spot! Saturn will show you three of its moons, tan and yellowish-beige cloud bands, its ring system, and the division between the two ring systems, the Cassini Division. Many People think that Saturn is the most beautiful and breath-taking planet. You can commonly pull star charts out of magazines such as Sky & Telescope, or download star charts off the internet to locate planets.

Deep Space Objects

Deep Space Objects, or DSOs, are objects outside of the Solar System such as galaxies, nebulae (Nebulae are clouds of gas and dust), and star clusters. Before you jump into the realm of Deep Space objects, make sure you have some practice finding simpler objects to avoid frustration.

![NGC 3370.jpg](NGC 3370.jpg)

To find DSOs, you should buy a star chart . If you live in a city, city lights wash out some of the darker objects, so you may want to head to a darker area for better observation. A good summer/fall DSO you should look for is M31, which is also known as the Andromeda Galaxy. Obviously, it is located in the constellation Andromeda. M42, also known as the Orion Nebula, is a good starter DSO for winter/early spring. It is located near Orion's Belt in the constellation Orion.

For more info on DSOs, go to Deep Space Astronomy. This page is specifically about DSOs and which ones to observe.

Cooling Before Looking

The typical night is cooler than the temperature in your house, right? That presents a problem to observing. When a telescope is stored inside a warm house, the telescope becomes warm, too. Therefore when you take it out on a cool night and immediately start looking at objects, you will see a blurry and wavy image. So before you observe, be sure to let your telescope cool down for about 30 minutes to an hour, depending on how cool it is outside, and the size of your telescope. For binoculars, you don't really need to make them cool down for very long, unless of course it's colder than usual outside.

Condensation also presents a problem on cooler nights. Frost is an even larger problem during the winter. For larger refractors and catadioptric telescopes, you will need protection from it. However, heated "dew caps" are available for all telescope sizes. Dew also tends to condense on the eyepiece. Every once in a while, take your eyepiece inside and let them dry, or use a hair dryer on low temperature. If your optics get wet or even soaked, don't freak out. It's just water, and it will dry off. Don't rub it with a towel, instead, try air-drying it.

Going to Darker Skies

If you want to get the best out of your observing session, go to the darkest skies nearest to you. Light pollution (LP) is the reason why. Here's what the Earth looks like from space because of LP:

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Now you get the point, right? In skies lit up by artificial light, it's hard to almost impossible to see Deep Space Objects.

Star Charts

What Are Star Charts? Planispheres?

There are two different types of star maps: Planispheres (or star finders) and regular Star Charts. Planispheres are rotating star charts that tell you where the constellations are located at any given time, day, and month. Regular Star Charts are huge fold-out maps of the sky that show you what constellations different Deep Space Objects (DSOs) are in.

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Remember: Planishperes and Star Charts work together. Planispheres tell you what constellations are up and when, and Star Charts tell you what DSOs are in the constellations.

How Do You Use Them?

To use a planisphere, set it to the current hour, day, and month. Hold it above your head with 12:00 am facing to the North. The constellations on the Planisphere will be shown in their correct positions in the sky. To use a Regular Star Chart, find out what constellations are in the sky at your time by using the planisphere, and look at those constellations on the Regular Star Chart. It will show you where different Deep Space Objects are located in those constellations.

Reccomended Star Charts?

In many amateur astronomers' opinions, the Sky Atlas 2000.0 is the best star chart. Instead of being a big fold out map, it is like an atlas. It shows almost every Deep Space Object that amateurs can observe. Another good "Star Chart" for beginners would be the Astro Pack. It has a Planisphere, a fold out Star Chart, a book showing the main constellations of the seasons and months, and a guide showing how to use your telescope.

Online Star Charts

There are also star charts that you can print out online. One printable starchart that I know of is very useful for beginning astronomers is from http://www.skymaps.com. It shows you not only a star chart, but also a list of things to observe. If you're a beginning astronomer, it gives you good stargazing tips and a list of objects visible to thew naked eye, or objects that you need a telescope to see.

Telescopes

What Type of Telescope Should I Get?

There are two types of ideal beginner telescopes: Refractors and Reflectors. If you're an astronomer who wants to view planets and other solar system objects, a Refractor would be better for you. Refractors are more fit for planets because they create crisper, sharper images. Another advantage of most Refractors is that they are easily on a tripod, which typically have a tracking system. Using this, the telecope will electronically move itself to stay centered on what you're observing. This also enables a Refractor user to do astrophotography.

If you're an amateur who wants to observe Deep Space Objects, a Reflector would be better for you. There are several reasons why this is so. First of all, a Reflector uses mirrors instead of lenses. In a Refractor, some entering light is eliminated by the lense. Also, mirrors are typically cheaper than lenses, so for the same price, you can get a larger Reflector than Refractor.

There are two popular styles of bases for Reflectors: Dobsonians mounts, and of course, tripods. Dobsonian mounted Reflectors tend to be cheaper, more portable, and can hold larger telescopes. Tripod mounted Reflectors are much more expensive and cannot hold larger telescopes, however they enable you to do astrophotography if you're willing to spend enough. I say this because if you want to put a 8" Reflector on a stable tripod, you'll be spending at least $1,000, where you'd be spending maybe $400 for one on a Dobsonian mount.

These beginning telescopes will typically cost around $300-$400, depending on the manufacturer and the quality of the optics.

There is a third, less familiar telescope design, known as Catadioptrics. These are a sort of combination between a Refractor and a Reflector, because they employ both lenses and mirrors. They look like very short, stubby Reflectors, typically on a tripod. Like Refractors, most have a tracking system and allow for astrophotography. The beauty of these telescopes is that they're the best of both worlds, performing well with both deep space and planetray astronomy. However, due to their high prices (starting at around $1,000) and complication, I would not reccomend them for beginning astronomers.

Pictures of the Celestron Refractor, Celestron Dobsonian, and Meade Cassegrain are from OPTcorp.com.

Aperture and Magnification???

It's actually simple. Aperture is the diameter of your telescope's mirror/lens, NOT the diameter of the opening of the tube. So why is aperture so important? The larger the aperture, the more light collecting power and magnification. Since a larger aperture means more light collection, you get a higher resolution, darker image.

A basic, beginning Refractor size is around 60-100mm. A common beginning Reflector size is around 6-8 inches. For a Reflector, the maximum magnification your telescope can handle, in theory, is around 50x per inch of aperture. For a Refractor, it's 100x per inch of aperture. The reason why a beginning astronomer shouldn't get such a large telescope is because they will get frustrated with the weight and difficulty with setting up. Also, a beginner shouldn't spend a lot of money on such a large telescope because they may end up not liking astronomy.

The maximum magnification really is not that important, because on most nights the maximum you could possibly crank with ANY telescope is around 250x. This is due to unstable atmospheric conditions. On some nights when the atmosphere is stable and there's low humidity, you should be able to get a lot more magnification on the moon and some planets with larger telescopes.

If a telescope is only advertised in magnification, ignore it. Many manufacturers know that the average person doesn't know a thing about magnification, so they pretend the telescope has a much higher magnification than it really does. A good telescope is advertised in the quality of the optics, the visible resolution, and the light-gathering capabilities.

However, magnification is completely irrelevant when observing DSO's. What is important with DSOs is, once again, the light-collecting power, which comes with aperture.

Telescope Brands?

There are many Telescope brands, but the most popular are Celestron, Meade, Orion, and Discovery. Consider all brands when shopping for your telescope.

Where Should I Buy My Telescope?

In my and many other astronomers' opinions, department store refractors are junk. They're always advertised in magnification and nothing else, their optics are usually poor, and their mounts are cheap and unstable. If you're going to buy a telescope, you should buy it at that telescope company's website or your local telescope dealer.

Eyepieces & Barlows

Important Eyepiece Terms

There is a large, confusing array of eyepieces available to the amateur astronomer, ranging from prices of $40 (Good for beginners) to $500 (The Nagler, Radians, and Panoptics). When shopping for an eyepiece, there are several things you should consider:

What Is A Barlow?

A barlow is like an eyepiece that when placed between the focuser and the eyepiece, doubles, triples, or even quadruples the power of your eyepiece. They are very useful because in a way, they double the amount of eyepieces that you have. Also, they allow you to use a high magnification with low power, high field of view eyepieces. If you use a normal high power eyepiece, you'll be looking through a peephole. Have you ever seen a really big eyepiece that says it's focal length is a lot smaller than it really is? That's because it has a built-in barlow. One bad thing about barlows is that since you're looking through more glass, the objects will appear dimmer. That isn't good for Deep Space Objects.

Recommended Beginner Eyepiece?

Although most telescopes come with two eyepieces, once you want more, get a Plossl. They are upper-middle class eyepieces that are excellent for beginning amatures. they cost around 50-$60.

Deep Space Astronomy

The Messier Objects

During the 18th century, Charles Joseph Messier, a famous astronomer, created a list of Deep Space Objects. During this period of time, telescopes and stargazing equipment were obviously not very advanced. That is why the Messier objects, or M objects (such as M31, M42, etc.) are great objects for beginning astronomers of any level of interest to observe. No matter what quality your equipment, most Messier objects will be visible in relatively dark skies. The Messier Objects are also the basis of any amateur astronomer's observational goals. Many astronomers will make a checklist of the Messier objects they have seen and have not seen. Sometimes, astronomers will start a "Messier Marathon". This is a personal challenge where an astronomer will try to observe as many Messier objects in a given amount of time as they possibly can. Really, seeing all the Messier objects is the only goal of many astronomers. Because really, there aren't many Non-Messier objects that are interesting! Don't get me wrong, there are some, but I'll discuss those later.

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NGC Objects

There are also some interesting objects called the NGC objects. The New General Catalog is a list of over 13,000 Deep Space Objects created in 1888. Besides the Messier list, this is the second most popular listing of Deep Space Objects. Although most of these will be hard to observe by a beginning amateur astronomer, many of them are very interesting. These objects are marked as NGC then a number, such as NGC 153.

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My Equipment

Currently, I have a 10" Orion Dobsonian telescope, a 6" Discovery DHQ Dobsonian telescope and Oberwerwerk 15x70 binoculars. Most of my eyepieces are plossls, great beginner eyepieces.. I also have an Orion Variable Polarizing filter, which is used to reduce the amount of light comming in to reveal more detail.

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My Resources

I have a Sky Atlas 2000.0 second edition, a great star chart for an amateur astronomer. I also have a planisphere, a necessity for any amateur astronomer. This came in the Astro Pack, which can be bought at most book stores. It is a great resource for beginning astronomers. For information on these two items, go to the page called "Star Charts".

My Only Picture

Well, I managed to take a picture through my 'scope of the Moon, but due to shaky hands and a dobsonian mount, it's not that clear.

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