The Amateur astronomy reference article from the English Wikipedia on 24-Jul-2004
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Amateur astronomy

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Amateur astronomy, often called back yard astronomy, is a hobby whose participants enjoy observing celestial objects. It is usually associated with viewing the night sky when most celestial objects and events are visible, but sometimes amateur astronomers also operate during the day for events such as sunspots and solar eclipses.

Amateur astronomers often look at the sky using nothing more than their eyes, but common tools for amateur astronomy include portable telescopes and binoculars.

Table of contents
1 Amateur astronomy and scientific research
2 Societies for amateur astronomy
3 Approaches to using amateur telescopes
4 Additional tools and activities
5 Beginning in amateur astronomy
6 See also

Amateur astronomy and scientific research

Unlike professional astronomy, scientific research is not typically the main goal for most amateur astronomers. Work of scientific merit is certainly possible, however, and many amateurs contribute to the knowledge base of professional astronomers very succesfully. Astronomy is often promoted as one of the few remaining sciences for which amateurs can still contribute useful data.

In particular, amateur astronomers often contribute towards activities such as monitoring the brightness changes of variable stars, helping to track asteroids, and observing occultations to determine both the shape of asteroids and the shape of the terrain on the edge of the Moon.

In the past and present, amateur astronomers have also played a major role in discovering new comets. Recently however, funding of projects such as the Lincoln Near-Earth Asteroid Research and Near Earth Asteroid Tracking projects has meant that most comets are now discovered by automated systems, long before it is possible for amateurs to see them.

Societies for amateur astronomy

There are a large number of amateur astronomical societies around the world that serve as a meeting point for those interested in amateur astronomy, whether they be people who are actively interested in observing or "armchair astronomers" who may be simply interested in the topic. Societies range widely in their goals, depending on a variety of factors such as geographic spread, local circumstances, size and membership. For instance, a local society in the middle of a large city may have regular meetings with speakers, focusing less on observing the night sky if the membership is less able to observe due to factors such as light pollution.

A telescope designed by Russell W. PorterEnlarge

A telescope designed by Russell W. Porter

It is common for local societies to hold regular meetings, which may include activities such as star parties. Other activities could include amateur telescope making, which was pioneered in America by Russell W. Porter, who later played a major role in design and construction of the Hale Telescope.

Approaches to using amateur telescopes

Amateur telescopes come in many shapes and sizes, both commercial and home-built. The preferences of people who use them often differ.

Star hopping

Some amateur astronomers prefer to learn the sky as accurately as they can, using maps to find their way between the stars. In this case a common approach is to use binoculars or a manually driven telescope, combined with star maps, to locate items of interest in the sky. The normal technique for doing this, by locating landmark stars and "hopping" between them, is called star hopping.

GOTO telescopes

More recently as technology has improved and prices have come down, automated "GOTO" telescopes have also become a popular choice. With these computer-driven telescopes, the user typically enters the name of the item they wish to look at, and the telescope finds it in the sky automatically with comparatively little further effort required by the user.

The main advantage of a "GOTO" telescope for an experienced amateur astronomer is the reduction of "wasted" time that may have otherwise been used in trying to find a particular object. This time can therefore be used more effectively for studying the object.

Comparing methodologies

There is significant (though usually light-hearted) debate within the hobby about which method is better. Promoters of the star hopping approach for finding items in the sky usually argue that they know the sky much better as a result. The manual method also tends to require simpler equipment with less calibration and setup time, and is therefore more versatile. Promoters of "GOTO" telescopes often argue that they are more interested in studying objects, and the reward of finding them or learning exactly where they are is not as important to them.

Additional tools and activities

As well as optical equipment, amateur astronomers use a variety of other tools such as warm clothes, maps, and computers loaded with specialised software. There is a range of astronomy software available, with the most widely appreciated being software that generates maps of the sky.

Some amateur astronomers also keep an observing log, in which they record details about what they have looked at and their impressions.

Beginning in amateur astronomy

There are a many ways for people to become involved in amateur astronomy and study the night sky. One option is to join a local astronomical society, the members of which will often be very happy to help a newcomer take a more active part. Some people also prefer to simply teach themselves, in which case there are likely to be a large amount of books in the local library.

Common objects that are observed early are the Moon and planets. Another thing that most newcomers to amateur astronomy become acquainted with are the more prominent constellations in the night sky. When reading maps and interpreting instructions for future star hopping, constellations are good starting points for identifying locations in the night sky. They are frequently referred to by amateur astronomers when discussing the location of items of interest when looked at with binoculars and telescopes.

Beginning with a GOTO telescope

A relatively new type of beginning amateur astronomer, brought about by the increased affordability of powerful "GOTO" telescopes, is one who begins with such a telescope. It is possible for an inexperienced person to immediately look at a large amount of deep sky objects in the night sky without necessarily having any prior experience or training.

There is currently some debate among many amateur astronomers about the merits of this approach to becoming involved in the hobby, and the effects that low-priced GOTO telescopes may be having. On one hand, amateur astronomy is being exposed to more people. On the other hand, some argue that there may be evidence that those who initially purchase powerful automated telescopes could become bored very quickly. These people argue that without the prior experience or a reasonable understanding of what to look for, it is more difficult to appreciate what is seen through a telescope.

Becoming acquainted with the night sky

Most tutors agree that it is very important to know one's way around the sky by means of the constellations. This ability forms a platform from which deeper explorations of the sky are then possible. Having learned the main constellations, a beginner may want to extend their hobby and buy a pair of binoculars or a telescope.

Using binoculars

With binoculars it is possible to see many deep sky objects (DSO's) albeit, not terribly well. Holding the binoculars can produce a shaky image. One way to improve the view is with the aid of a sturdy tripod mount to steady the view through the binoculars. Binoculars are still limited in range, however, most of the Messier catalogue should be visible and a great many NGC's as well, especially near the Milky Way.

Using a telescope

With a telescope, the sky really comes alive, especially one that has an aperture of six inches or more. Some amateur telescopes are built by their owners from scratch. But many good quality telescopes can be purchased from reputable companies. Thousands of DSO's are visible in a telescope and the determined amateur with a large (about 41 cm) telescope can push this to tens of thousands or more.

Another type of telescope to consider, especially if the amateur is observing with children, is a wide-field telescope, such as Edmund Scientific's f/4 Astroscan compact reflector. This type of telescope is typically a short tube reflector and has an aperture of only 80 to 120 mm (3 1/4 to 4 3/4 inches), but is easier to target an object, since it offers a much wider field of view. With the aid of high power lenses (i.e. eyepieces), the amateur can zoom in on planets and some of the closer DSOs. It is the best of a blend of a telescope's narrow long range light gathering ability with a binocular's wider field of view. With any telescope, though, the mount is the most important feature. A tripod that doesn't shake every time one uses it is a must. Too many amateur astronomers give up because they have a hard time targeting an object. If the mounting tripod is rock solid, the amateur can enjoy their time observing the heavens instead of fighting with the telescope.

Astrophotography

A photo taken of Comet Hale Bopp using a standard 35 mm camera with a 50 mm lens and 400 ISO film.  The exposure was taken for 10 seconds on a tripod using a shutter cable releaseEnlarge

A photo taken of Comet Hale Bopp using a standard 35 mm camera with a 50 mm lens and 400 ISO film. The exposure was taken for 10 seconds on a tripod using a shutter cable release

The next step in an amateur astronomers quest for more space adventure comes with the purchase of a good camera for Astrophotography. Starting out with a good 35 mm camera with a 50 mm lens mounted on a tripod and using a cable release and 400 or faster speed film, the amateur can capture some nice pictures of the planets and some larger nebula, like the Orion Nebula. Some of the larger comets and prolific meteor showers can be photographed this way as well.

As one progresses, cameras can be mounted directly on to telescopes, capturing on film many DSOs. Special films and even the technique of hypering the film has been employed by the amateur. Many publications accept these astrophotos in their magazines, ie., Astronomy Magazine.

Suggested reading

Some good books for amateur astronomers to start with:

See also