Amateur astronomy
748
224409008
2008-07-08T18:48:50Z
Skeptic2
2395584
Deleted advertising link.
{{Citations missing|date=December 2007}}
[[Image:Astronomy Amateur 3 V2.jpg|thumb|right|250px|Amateur astronomers watch the night sky during the [[Perseids|Perseid]] meteor shower]]
'''Amateur astronomy''', a subset of [[astronomy]], is a [[hobby]] whose participants enjoy studying and observing celestial objects.
== Overview ==
The amateur astronomer is one who does not depend on the field of astronomy as a primary source of [[income]] or support, and does not have a [[professional degree]] or advanced academic training. Many amateurs are beginners, while others have a high degree in astronomy and often assist and work alongside professional astronomers.
Amateur astronomy 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 [[sunspot]]s and [[solar eclipse]]s. Amateur astronomers often look at the sky using nothing more than their eyes, but common tools for amateur astronomy include portable [[optical telescope|telescopes]] and [[binoculars]].
People have studied the sky throughout history in an amateur framework, without any formal method of funding. It is only within about the past century, however, that amateur astronomy has become an activity clearly distinguished from professional astronomy, and other related activities.
== Amateur astronomy objectives ==
Collectively, amateur astronomers observe a variety of celestial objects and [[phenomenon|phenomena]]. Common targets of amateur astronomers include the [[Moon]], [[planet]]s, [[star]]s, [[comet]]s, [[meteor shower]]s, and a variety of [[deep sky object]]s such as [[star cluster]]s, [[galaxy|galaxies]], and [[nebula]]e. Many amateurs like to specialise in observing particular objects, types of objects, or types of events which interest them. One branch of amateur astronomy, amateur [[astrophotography]], involves the taking of photos of the night sky. Astrophotography has become more popular for amateurs in recent times, as relatively sophisticated equipment, such as high quality [[CCD camera]]s, has become more affordable.
Most amateurs work at [[visible spectrum|visible wavelength]]s, but a small minority experiment with wavelengths outside the visible spectrum. The pioneer of amateur radio astronomy was [[Karl Guthe Jansky|Karl Jansky]] who started observing the sky at [[radio frequency|radio wavelength]]s in the 1930s, and interest has increased over time. Non-visual amateur astronomy includes the use of [[infrared filter]]s on conventional telescopes, and also the use of [[radio telescope]]s. Some amateur astronomers use home-made radio telescopes, while others use radio telescopes that were originally built for astronomy research but have since been made available for use by amateurs. The [[One-Mile Telescope]] is one such example.
== Common tools ==
Amateur astronomers use a range of [[instrument]]s to study the [[sky]], depending on a combination of their interests and resources. Methods include simply looking at the night sky with the [[naked eye]], using [[binoculars]], and using a variety of [[telescope]]s of varying power and quality, as well as additional sophisticated equipment, such as [[camera]]s, to study light from the sky in both the visual and non-visual parts of the [[spectrum]]. Commercial telescopes are available and used, but in some places it is also common for amateur astronomers to build (or commission the building of) their own [[customization|custom]] telescope. Some people even focus on [[amateur telescope making]] as their primary interest within the hobby of amateur astronomy.
Although specialised and experienced amateur astronomers tend to acquire more specialised and more powerful equipment over time, relatively simple equipment is often preferred for certain tasks. Binoculars, for instance, although generally of lower power than the majority of telescopes, also tend to provide a wider [[field of view]], which is preferable for looking at some objects in the night sky.
Amateur astronomers also use [[star charts]] that, depending on experience and intentions, may range from simple [[planisphere]]s through to detailed charts of very specific areas of the night sky. A range of [[astronomy software]] is available and used by amateur astronomers, including software that generates maps of the sky, software to assist with astrophotography, and software to perform various calculations pertaining to astronomical phenomena.
Amateur astronomers often like to keep records of their observations, which usually takes the form of an [[astronomical observing log|observing log]]. Observing logs typically record details about which objects were observed and when, as well as describing the details that were seen. Sketching is sometimes used within logs, and photographic records of observations have also been used in recent times.
The Internet is an essential tool of amateur astronomers. Almost all astronomy clubs, even those with very few members, have a web site. The popularity of CCD imaging among amateurs means large numbers of web sites written by individuals about their images and equipment. Much of the social interaction of amateur astronomy occurs on mailing lists or discussion groups. Yahoo groups and Google groups host numerous astronomy lists. A great deal of the commerce of amateur astronomy, the buying and selling of equipment, occurs online. Many amateurs use online tools to plan their nightly observing sessions using tools such as the [[Clear Sky Chart]].
== Common techniques ==
Many methods are used in amateur astronomy to locate items in the sky, but most are variations of a few specific techniques.
=== Star hopping ===
'''[[Star hopping]]''' is a method often used by amateur astronomers with low-tech equipment such as binoculars or a manually driven telescope. It involves the use of maps (or memory) to locate known [[landmark]] stars, and "hopping" between them. Because of its [[simplicity]], star hopping is a very common method for finding objects that are close to naked-eye stars.
More advanced methods of locating objects in the sky include ''setting circles'', which assist with pointing telescopes to positions in the sky that are known to contain objects of interest, and ''GOTO telescopes'', which are fully automated telescopes that are capable of locating objects on demand (having first been [[calibration|calibrated]]).
=== Setting circles ===
'''[[Setting circles]]''' are [[angular measurement]] scales that can be placed on the two main [[rotation axis|rotation axes]] of some telescopes. Since the widespread adoption of digital setting circles, any classical engraved setting circle is now specifically identified as an "analog setting circle" (ASC). By knowing the [[coordinate]]s of an object (usually given in [[equatorial coordinates]]), the telescope user can use the setting circle to align the telescope in the appropriate direction before looking through its [[eyepiece]]. A computerized setting circle is called a "digital setting circle" (DSC). Although digital setting circles can be used to display a telescope's [[right ascension|RA]] and [[declination|Dec]] coordinates, they are not simply a digital [[read-out]] of what can be seen on the telescope's analog setting circles. As with go-to telescopes, digital setting circle computers (commercial names include Argo Navis, Sky Commander, and NGC Max) actually contain databases of tens of thousands of celestial objects and projections of planet positions.
To find an object, such as globular cluster [[NGC 6712]], one does not need to look up the RA and Dec coordinates in a book, and then move the telescope to those numerical readings. Rather, the object is chosen from the database and arrow markers appear in the display which indicate the direction to move the telescope. The telescope is moved until the distance value reaches zero. When both the RA and Dec axes are thus "zeroed out", the object should be in the eyepiece. The user therefore does not have to go back and forth from some other database (such as a book or laptop) to match the desired object's listed coordinates to the coordinates on the telescope. However, many DSCs, and also go-to systems, can work in conjunction with laptop sky programs.
Computerized systems provide the further advantage of computing coordinate precession. Traditional printed sources are subtitled by the ''epoch'' year, which refers to the positions of celestial objects at a given time to the nearest year (e.g., [[J2005]], [[J2007]]). Most such printed sources have been updated for intervals of only about every fifty years (e.g., [[J1900]], [[J1950]], [[J2000]]). Computerized sources, on the other hand, are able to calculate the right ascension and declination of the "epoch of date" to the exact instant of observation.
===GoTo telescopes===
'''[[GoTo (telescopes)|GOTO telescopes]]''' have become more popular in recent times as technology has improved and prices have been reduced. With these computer-driven telescopes, the user typically enters the name of the item of interest and the mechanics of the telescope point the telescope towards that item automatically. They have several notable advantages for amateur astronomers intent on [[research]]. For example, GOTO telescopes tend to be faster for locating items of interest than star hopping, allowing more time for studying of the object. GOTO also allows manufacturers to add equatorial tracking to mechanically simpler alt-azmuth telescope mounts, allowing them to produce an over all less expensive product.
Because GOTO telescopes have become increasingly affordable, a new ''type'' of beginning amateur astronomer has emerged, in that GOTO telescopes offer a form of instant gratification, sometimes allowing difficult objects to be found quickly without requiring the experience of learning to find them.
====The GoTo debate====
In the early 1990s, the amateur astronomy community engaged in some debate, usually light-hearted, about which method is superior. Some astronomers argued that beginning with the lower end of technology and using star hopping techniques is an excellent method of learning the sky, and that a good knowledge of the night sky can be advantageous for people who prefer simpler equipment with less calibration and setup time, and is therefore more versatile. Star hopping involves the use of printed media that is dependent on computer generated sources. The user prints out star maps at home or uses books, [[star cartography|atlases]], and magazine articles that have computer generated graphics in them to aid in the quest to find an object.
GOTO telescopes, on the other hand, do make the hobby more accessible. They may be preferred by people who are more serious about studying objects, because less time and effort are required for finding objects when they are well prepared. But digital setting circle or go-to systems also provide touring functions whereby the user can set parameters such as [[apparent magnitude|magnitude]] and class of object, and, for example, view a series of [[planetary nebula]]e in [[Cygnus (constellation)|Cygnus]]. A user who has discovered that his list of close [[double star]]s is impossible to view because of the seeing conditions can select an alternative viewing program within minutes. Many middle-aged and older amateur astronomers discovered that electronic pointing systems not only were convenient but spared them the difficult postures and associated aches and pains that go with pointing a telescope at [[zenith]] (with the common straight-through finder) or near to the [[horizon]] (on elevated mounts the finder can be out of reach). The explosion of astrophotography, in which a [[webcam]] or [[charge-coupled device|CCD]] camera is mounted on a telescope and downloads data to a nearby laptop, further enhanced demand for [[robotic telescope|robotic systems]] that would point the telescope while the operator could stay seated and set imaging parameters.
=== Imaging techniques ===
Amateur astronomers engage in many imaging techniques including [[film]] and [[charge-coupled device | CCD]] [[astrophotography]]. Because CCD imagers are linear, [[image processing]] may be used to subtract away the effects of lightpollution, which has increased the popularity of astrophotography in urban areas{{Fact|date=January 2008}}.
== Scientific research ==
[[Scientific method|Scientific research]] is most often not the ''main'' goal for many amateur astronomers, unlike professional astronomy. Work of scientific merit is possible, however, and many amateurs successfully contribute to the knowledge base of professional astronomers. Astronomy is sometimes promoted as one of the few remaining sciences for which amateurs can still contribute useful data. To recognise this, the [[Astronomical Society of the Pacific]] annually gives [[Amateur Achievement Award of Astronomical Society of the Pacific|Amateur Achievement Awards]] for significant contributions to astronomy by amateurs.
The majority of scientific contributions by amateur astronomers are in the area of data collection. In particular, this applies where large numbers of amateur astronomers with small telescopes are more effective than the relatively small number of large telescopes that are available to professional astronomers. Several organisations, such as the [http://cbastro.org Center for Backyard Astrophysics], exist to help coordinate these contributions.
Amateur astronomers often contribute toward activities such as monitoring the changes in brightness of [[variable star]]s, helping to track [[asteroid]]s, and observing [[occultation]]s to determine both the shape of asteroids and the shape of the terrain on the apparent edge of the [[Moon]] as seen from Earth. With more advanced equipment, but still cheap in comparison to professional setups, amateur astronomers can measure the light spectrum emitted from astronomical objects, which can yield high-quality scientific data if the measurements are performed with due care. A relatively recent role for amateur astronomers is searching for overlooked phenomena (e.g., [[Kreutz Sungrazers]]) in the vast libraries of digital images and other data captured by Earth and space based observatories, much of which is available over the Internet.
In the past and present, amateur astronomers have played a major role in discovering new [[comet]]s. Recently however, funding of projects such as the [[LINEAR|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 ==
There is a large number of amateur [[astronomical society|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]].
It is common for local societies to hold regular meetings, which may include activities such as [[star party|star parties]] or presentations. Societies are also a meeting point for people with particular interests, such as [[amateur telescope making]].
== Famous amateur astronomers ==
* [[George Alcock]], discoverer of comets and novae.
*[[John Dobson (astronomer)|John Dobson]] perfected the [[Dobsonian telescope]] mount that revolutionised the building of large-apature [[Newtonian reflector]] telescopes for faint-object observing.
*[[Will Hay]], the famous comedian and actor, who discovered a white spot on Saturn.
*[[David H. Levy]] discovered or co-discovered 22 comets including [[Comet Shoemaker-Levy 9]], the most for any individual.
*[[Leslie Peltier]] was a prolific discoverer of comets and well-known observer of variable stars.
*[[Russell W. Porter]] founded [[Stellafane]] and has been referred to as the "founder of [[amateur telescope making]]". {{Fact|date=January 2008}}
*[[Isaac Roberts]] was the first to apply photography to astronomy.
*Amateur [[Thomas Bopp]] shared the discovery of [[Comet Hale-Bopp]] in 1997 with unemployed PhD physicist [[Alan Hale (astronomer)|Alan Hale]].
*[[Patrick Moore|Sir Patrick Moore]], presenter of the BBC's long-running ''[[The Sky at Night]]'' and author of many books on astronomy.
*[[Robert Evans (astronomer)|Robert Owen Evans]] is a minister of the [[Uniting Church in Australia]] and an amateur astronomer who holds the all-time record for visual discoveries of [[supernovae]].
== References ==
*{{cite web | url = http://www.aavso.org/
| title = American Association of Variable Star Observers | publisher = AAVSO | language = English | accessdate = 2006-08-24 }}
*{{cite web | url = http://www.amsmeteors.org/ | title = The American Meteor Society | language = English | accessdate = 2006-08-24 }}
*{{cite web | url = http://www.lunar-occultations.com/iota/iotandx.htm | title = The International Occultation Timing Association | language = English | accessdate = 2006-08-24 }}
*{{cite web | url = http://cfa-www.harvard.edu/ep/comet/comet6.html | title = Edgar Wilson Award | publisher = Harvard-Smithsonian Center for Astrophysics | language = English | accessdate = 2006-08-24 }}
{{reflist}}
== See also ==
* [[Amateur telescope making]]
* [[Astronomical object]]
* [[Observation]]
* [[Observational astronomy]]
* [[Skygazing]]
* [[Star party]]
* [[Clear Sky Chart]] Weather forecasts designed for amateur astronomers.
Amateur astronomy organizations:
* [[American Association of Variable Star Observers]]
* [[Association of Lunar and Planetary Observers]]
* [[Astronomical League]]
* [[Society for Popular Astronomy]] (UK)
* [[Royal Astronomical Society of Canada]]
* [[Federation of Astronomical Societies]] (UK)
Prizes recognizing amateur astronomers:
* [[Amateur Achievement Award of Astronomical Society of the Pacific]]
* [[Chambliss Amateur Achievement Award]]
== Further reading ==
* ''The Stars: A New Way to See Them'', by Hans Augusto Rey, ISBN 0-395-08121-1
* ''NightWatch: An Equinox Guide to Viewing the Universe'', by [[Terence Dickinson]], ISBN 0-920656-89-7
* ''The Backyard Astronomer's Guide'', by Terence Dickinson and Alan Dyer, ISBN 0-921820-11-9
* ''Turn Left at Orion'', by [[Guy Consolmagno]], ISBN 0-521-34090-X
* ''Skywatching'', by David H. Levy and John O'Byrne, ISBN 0-7835-4751-X
* ''Seeing in the Dark: How Backyard Stargazers Are Probing Deep Space and Guarding Earth from Interplanetary Peril'', by [[Timothy Ferris]], ISBN 0-684-86579-3
* ''The Complete Manual Of Amateur Astronomy'', by P. Clay Sherrod
* ''Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System'' (3 vols.), by [[Robert Burnham, Jr.]], (Vol 1) ISBN 0-486-23567-X, (Vol 2) ISBN 0-486-23568-8, (Vol 3) ISBN 0-486-23673-0
* ''Stars and Planets Guide'', by [[Ian Ridpath]] and [[Wil Tirion]]. Collins, London. ISBN 978-0007251209. Princeton University Press, Princeton. ISBN 978-0691135564.
* ''The Monthly Sky Guide'', by [[Ian Ridpath]] and [[Wil Tirion]]. Cambridge University Press, ISBN 978-0521684354.
* ''The Usbourne Complete Book of Astronomy and Space'', by Lisa Miles and Alastair Smith. Usbourne. ISBN 0-7460-3105-X
* ''Collins How to Identify Night Sky'', by Storm Dunlop and [[Wil Tirion]]. Collins, London. ISBN 0-00-718164-7
== External links ==
<!--Links added here should lead to websites that further describe Amateur astronomy, not sites about "how-to" conduct Amateur astronomy (see: WP:NOT#HOWTO and WP:EL) -->
* [http://www.bambi.net/ Amateur Search for Extraterrestrial Intelligence]
* [http://www.amateurastronomy.com/ Amateur Astronomy Magazine]
[[Category:Amateur astronomy]]
[[de:Amateurastronomie]]
[[el:Ερασιτεχνική Αστρονομία]]
[[es:Astronomía amateur]]
[[fr:Astronomie amateur]]
[[hr:Amaterska astronomija]]
[[it:Astronomia amatoriale]]
[[lb:Amateurastronom]]
[[hu:Amatőrcsillagászat]]
[[nl:Amateurastronomie]]
[[ja:天体観測]]
[[ru:Любительская астрономия]]
[[sk:Amatérska astronómia]]
[[fi:Tähtitieteen harrastus]]
[[th:ดาราศาสตร์สมัครเล่น]]
[[tr:Amatör Astronomi]]
[[zh:業餘天文學]]