Amateur astronomy
Encyclopedia
Amateur astronomy, also called backyard astronomy and stargazing, is a hobby
whose participants enjoy watching the night sky
(and the day sky too, for sunspots, eclipses, etc.), and the plethora of objects found in it, mainly with portable telescopes and binoculars. Even though scientific research is not their main goal, many amateur astronomers make a contribution to astronomy by monitoring variable stars, tracking asteroids and discovering transient objects, such as comets.
or support, and does not have a professional degree or advanced academic training in the subject. Many amateurs are beginners or hobby
ists, while others have a high degree of experience 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 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.
. Common targets of amateur astronomers include the Moon
, planet
s, star
s, comet
s, meteor shower
s, and a variety of deep sky objects such as star cluster
s, 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 cameras, has become more affordable.
Most amateurs work at visible wavelengths
, but a small minority experiment with wavelengths outside the visible spectrum. An early pioneer of radio astronomy
was Grote Reber
, an amateur astronomer who constructed the first purpose built radio telescope
in the late 1930s to follow up on the discovery of radio wavelength
emissions from space by Karl Jansky
. 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.
, 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 optical 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 new and used, but in some places it is also common for amateur astronomers to build (or commission the building of) their own custom telescope. Some people even focus on amateur telescope making
as their primary interest within the hobby of amateur astronomy.
Although specialized and experienced amateur astronomers tend to acquire more specialized 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, observation scheduling software, 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 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. The popularity of CCD imaging among amateurs has led to large numbers of web sites being written by individuals about their images and equipment. Much of the social interaction of amateur astronomy occurs on mailing lists or discussion groups. Discussion group servers 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
.
stars, and "hopping" between them, often with the aid of a finderscope
. 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 telescope mount
s with 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 calibrated
).
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 coordinates 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 RA
and 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) 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.
. 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-azimuth telescope mounts, allowing them to produce an over all less expensive product. GOTO telescopes usually have to be calibrated using alignment stars in order to provide accurate tracking and positioning. However, several telescope manufacturers have recently developed telescope systems that are calibrated with the use of built-in GPS, decreasing the time it takes to set up a telescope at the start of an observing session.
.
and CCD
astrophotography
. Because CCD imagers are linear, image processing
may be used to subtract away the effects of light pollution, which has increased the popularity of astrophotography in urban areas.
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 recognize this, the Astronomical Society of the Pacific
annually gives 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 organizations, such as the American Association of Variable Star Observers
and 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 and supernovae, 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 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.
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 simply be 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 parties
or presentations. Societies are also a meeting point for people with particular interests, such as amateur telescope making
.
Hobby
A hobby is a regular activity or interest that is undertaken for pleasure, typically done during one's leisure time.- Etymology :A hobby horse is a wooden or wickerwork toy made to be ridden just like a real horse...
whose participants enjoy watching the night sky
Night sky
The term night sky refers to the sky as seen at night. The term is usually associated with astronomy, with reference to views of celestial bodies such as stars, the Moon, and planets that become visible on a clear night after the Sun has set. Natural light sources in a night sky include moonlight,...
(and the day sky too, for sunspots, eclipses, etc.), and the plethora of objects found in it, mainly with portable telescopes and binoculars. Even though scientific research is not their main goal, many amateur astronomers make a contribution to astronomy by monitoring variable stars, tracking asteroids and discovering transient objects, such as comets.
Overview
The typical amateur astronomer is one who does not depend on the field of astronomy as a primary source of incomeIncome
Income is the consumption and savings opportunity gained by an entity within a specified time frame, which is generally expressed in monetary terms. However, for households and individuals, "income is the sum of all the wages, salaries, profits, interests payments, rents and other forms of earnings...
or support, and does not have a professional degree or advanced academic training in the subject. Many amateurs are beginners or hobby
Hobby
A hobby is a regular activity or interest that is undertaken for pleasure, typically done during one's leisure time.- Etymology :A hobby horse is a wooden or wickerwork toy made to be ridden just like a real horse...
ists, while others have a high degree of experience in astronomy and often assist and work alongside professional astronomers.
Amateur astronomy is usually associated with viewing the night sky
Night sky
The term night sky refers to the sky as seen at night. The term is usually associated with astronomy, with reference to views of celestial bodies such as stars, the Moon, and planets that become visible on a clear night after the Sun has set. Natural light sources in a night sky include moonlight,...
when most celestial objects and events are visible, but sometimes amateur astronomers also operate during the day for events such as sunspot
Sunspot
Sunspots are temporary phenomena on the photosphere of the Sun that appear visibly as dark spots compared to surrounding regions. They are caused by intense magnetic activity, which inhibits convection by an effect comparable to the eddy current brake, forming areas of reduced surface temperature....
s and solar eclipse
Solar eclipse
As seen from the Earth, a solar eclipse occurs when the Moon passes between the Sun and the Earth, and the Moon fully or partially blocks the Sun as viewed from a location on Earth. This can happen only during a new moon, when the Sun and the Moon are in conjunction as seen from Earth. At least...
s. Amateur astronomers often look at the sky using nothing more than their eyes, but common tools for amateur astronomy include portable telescopes
Optical telescope
An optical telescope is a telescope which is used to gather and focus light mainly from the visible part of the electromagnetic spectrum for directly viewing a magnified image for making a photograph, or collecting data through electronic image sensors....
and binoculars
Binoculars
Binoculars, field glasses or binocular telescopes are a pair of identical or mirror-symmetrical telescopes mounted side-by-side and aligned to point accurately in the same direction, allowing the viewer to use both eyes when viewing distant objects...
.
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 phenomenaPhenomenon
A phenomenon , plural phenomena, is any observable occurrence. Phenomena are often, but not always, understood as 'appearances' or 'experiences'...
. Common targets of amateur astronomers include the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
, planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...
s, star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
s, comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
s, meteor shower
Meteor shower
A meteor shower is a celestial event in which a number of meteors are observed to radiate from one point in the night sky. These meteors are caused by streams of cosmic debris called meteoroids entering Earth's atmosphere at extremely high speeds on parallel trajectories. Most meteors are smaller...
s, and a variety of deep sky objects such as star cluster
Star cluster
Star clusters or star clouds are groups of stars. Two types of star clusters can be distinguished: globular clusters are tight groups of hundreds of thousands of very old stars which are gravitationally bound, while open clusters, more loosely clustered groups of stars, generally contain less than...
s, galaxies
Galaxy
A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...
, and nebula
Nebula
A nebula is an interstellar cloud of dust, hydrogen gas, helium gas and other ionized gases...
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
Astrophotography
Astrophotography is a specialized type of photography that entails recording images of astronomical objects and large areas of the night sky. The first photographs of an astronomical object were taken in the 1840s, but it was not until the late 19th century that advances in technology allowed for...
, 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 cameras, has become more affordable.
Most amateurs work at visible wavelengths
Visible spectrum
The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 390 to 750 nm. In terms of...
, but a small minority experiment with wavelengths outside the visible spectrum. An early pioneer of radio astronomy
Radio astronomy
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The initial detection of radio waves from an astronomical object was made in the 1930s, when Karl Jansky observed radiation coming from the Milky Way. Subsequent observations have identified a number of...
was Grote Reber
Grote Reber
Grote Reber was an amateur astronomer and pioneer of radio astronomy. He was instrumental in investigating and extending Karl Jansky's pioneering work, and conducted the first sky survey in the radio frequencies...
, an amateur astronomer who constructed the first purpose built radio telescope
Radio telescope
A radio telescope is a form of directional radio antenna used in radio astronomy. The same types of antennas are also used in tracking and collecting data from satellites and space probes...
in the late 1930s to follow up on the discovery of radio wavelength
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
emissions from space by Karl Jansky
Karl Guthe Jansky
Karl Guthe Jansky was an American physicist and radio engineer who in August 1931 first discovered radio waves emanating from the Milky Way. He is considered one of the founding figures of radio astronomy.- Early life :...
. Non-visual amateur astronomy includes the use of infrared filter
Infrared filter
Infrared cut-off filters, sometimes called IR filters or heat-absorbing filters, are designed to reflect or block mid-infrared wavelengths while passing visible light. They are often used in devices with bright incandescent light bulbs to prevent unwanted heating...
s on conventional telescopes, and also the use of radio telescope
Radio telescope
A radio telescope is a form of directional radio antenna used in radio astronomy. The same types of antennas are also used in tracking and collecting data from satellites and space probes...
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
One-Mile Telescope
The One-Mile Telescope at the Mullard Radio Astronomy Observatory is an array of radio telescopes designed to perform aperture synthesis interferometry.- History :The One Mile Telescope was completed by the Radio Astronomy Group of Cambridge...
is one such example.
Common tools
Amateur astronomers use a range of instruments to study the skySky
The sky is the part of the atmosphere or outer space visible from the surface of any astronomical object. It is difficult to define precisely for several reasons. During daylight, the sky of Earth has the appearance of a pale blue surface because the air scatters the sunlight. The sky is sometimes...
, depending on a combination of their interests and resources. Methods include simply looking at the night sky with the naked eye
Naked eye
The naked eye is a figure of speech referring to human visual perception unaided by a magnifying or light-collecting optical device, such as a telescope or microscope. Vision corrected to normal acuity using corrective lenses is considered "naked"...
, using binoculars
Binoculars
Binoculars, field glasses or binocular telescopes are a pair of identical or mirror-symmetrical telescopes mounted side-by-side and aligned to point accurately in the same direction, allowing the viewer to use both eyes when viewing distant objects...
, and using a variety of optical telescope
Optical telescope
An optical telescope is a telescope which is used to gather and focus light mainly from the visible part of the electromagnetic spectrum for directly viewing a magnified image for making a photograph, or collecting data through electronic image sensors....
s of varying power and quality, as well as additional sophisticated equipment, such as camera
Camera
A camera is a device that records and stores images. These images may be still photographs or moving images such as videos or movies. The term camera comes from the camera obscura , an early mechanism for projecting images...
s, to study light from the sky in both the visual and non-visual parts of the spectrum
Spectrum
A spectrum is a condition that is not limited to a specific set of values but can vary infinitely within a continuum. The word saw its first scientific use within the field of optics to describe the rainbow of colors in visible light when separated using a prism; it has since been applied by...
. Commercial telescopes are available new and used, but in some places it is also common for amateur astronomers to build (or commission the building of) their own custom telescope. Some people even focus on amateur telescope making
Amateur telescope making
Amateur telescope making is the activity of building telescopes as a hobby, as opposed to being a paid professional. Amateur telescope makers build their instruments for personal enjoyment of a technical challenge, as a way to obtain an inexpensive or personally customized telescope, or as a...
as their primary interest within the hobby of amateur astronomy.
Although specialized and experienced amateur astronomers tend to acquire more specialized 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
Field of view
The field of view is the extent of the observable world that is seen at any given moment....
, 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
Planisphere
A planisphere is a star chart analog computing instrument in the form of two adjustable disks that rotate on a common pivot. It can be adjusted to display the visible stars for any time and date. It is an instrument to assist in learning how to recognize stars and constellations...
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, observation scheduling software, 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 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. The popularity of CCD imaging among amateurs has led to large numbers of web sites being written by individuals about their images and equipment. Much of the social interaction of amateur astronomy occurs on mailing lists or discussion groups. Discussion group servers 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
Clear Sky Chart
Clear Sky Charts are web graphics which deliver weather forecasts designed specifically for astronomers.They forecast the cloud cover, transparency and astronomical seeing, parameters which are not forecast by civil or aviation forecasts. They forecast hourly data, but are limited to forecasting...
.
Common techniques
While a number of interesting celestial objects are readily identified by the naked eye, sometimes with the aid of a star chart, many others are so faint or inconspicuous that technical means are necessary to locate them. Many methods are used in amateur astronomy, 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 landmarkLandmark
This is a list of landmarks around the world.Landmarks may be split into two categories - natural phenomena and man-made features, like buildings, bridges, statues, public squares and so forth...
stars, and "hopping" between them, often with the aid of a finderscope
Finderscope
A Finderscope is a small auxiliary telescope mounted atop the main astronomical telescope and pointed in the same direction. The finderscope usually has a much smaller magnification than the main telescope can provide and therefore can see more of the sky. This helps in locating the desired...
. Because of its simplicity
Simplicity
Simplicity is the state or quality of being simple. It usually relates to the burden which a thing puts on someone trying to explain or understand it. Something which is easy to understand or explain is simple, in contrast to something complicated...
, 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 telescope mount
Telescope mount
A telescope mount is a mechanical structure which supports a telescope. Telescope mounts are designed to support the mass of the telescope and allow for accurate pointing of the instrument...
s with 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 calibrated
Calibration
Calibration is a comparison between measurements – one of known magnitude or correctness made or set with one device and another measurement made in as similar a way as possible with a second device....
).
Setting circles
Setting circles are angular measurement scales that can be placed on the two main rotation axesRotation around a fixed axis
Rotation around a fixed axis is a special case of rotational motion. The fixed axis hypothesis exclude the possibility of a moving axis, and cannot describe such phenomena as wobbling or precession. According to Euler's rotation theorem, simultaneous rotation around more than one axis at the same...
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 coordinates 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
Eyepiece
An eyepiece, or ocular lens, is a type of lens that is attached to a variety of optical devices such as telescopes and microscopes. It is so named because it is usually the lens that is closest to the eye when someone looks through the device. The objective lens or mirror collects light and brings...
. A computerized setting circle is called a "digital setting circle" (DSC). Although digital setting circles can be used to display a telescope's RA
Right ascension
Right ascension is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. The other coordinate is the declination.-Explanation:...
and Dec
Declination
In astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is comparable to geographic latitude, but projected onto the celestial sphere. Declination is measured in degrees north and...
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) contain databases of tens of thousands of celestial objects and projections of planet positions.
To find an object, such as globular cluster NGC 6712
NGC 6712
NGC 6712 is a globular cluster that was probably discovered by Le Gentil on July 9, 1749 when investigating the Milky Way star cloud in Aquila. He described it as a "true nebula," in contrast to the open star cluster M11. Independently discovered by William Herschel on June 16, 1784 and cataloged...
, 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
Epoch (astronomy)
In astronomy, an epoch is a moment in time used as a reference point for some time-varying astronomical quantity, such as celestial coordinates, or elliptical orbital elements of a celestial body, where these are subject to perturbations and vary with time...
, 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 have become more popular since the 1980s 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 researchResearch
Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...
. 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-azimuth telescope mounts, allowing them to produce an over all less expensive product. GOTO telescopes usually have to be calibrated using alignment stars in order to provide accurate tracking and positioning. However, several telescope manufacturers have recently developed telescope systems that are calibrated with the use of built-in GPS, decreasing the time it takes to set up a telescope at the start of an observing session.
Remote control telescopes
With the development of fast Internet in the last part of the 20th century along with advances in computer controlled telescope mounts and CCD cameras 'Remote Telescope' astronomy is now a viable means for amateur astronomers not aligned with major telescope facilities to partake in research and deep sky imaging. This enables anyone to control a telescope a large distance away in a dark location. The observers can image through the telescopes using CCD cameras. The digital data collected by the telescope is then transmitted and displayed to the user by means of the Internet. An example of a digital remote telescope operation for public use via the Internet is the The Bareket ObservatoryBareket observatory
The Bareket Observatory is an astronomical educational observatory owned and operated by the Bareket family. It is located east of the city of Maccabim, near Modiin....
.
Imaging techniques
Amateur astronomers engage in many imaging techniques including filmFilm
A film, also called a movie or motion picture, is a series of still or moving images. It is produced by recording photographic images with cameras, or by creating images using animation techniques or visual effects...
and CCD
Charge-coupled device
A charge-coupled device is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This is achieved by "shifting" the signals between stages within the device one at a time...
astrophotography
Astrophotography
Astrophotography is a specialized type of photography that entails recording images of astronomical objects and large areas of the night sky. The first photographs of an astronomical object were taken in the 1840s, but it was not until the late 19th century that advances in technology allowed for...
. Because CCD imagers are linear, image processing
Image processing
In electrical engineering and computer science, image processing is any form of signal processing for which the input is an image, such as a photograph or video frame; the output of image processing may be either an image or, a set of characteristics or parameters related to the image...
may be used to subtract away the effects of light pollution, which has increased the popularity of astrophotography in urban areas.
Scientific research
Scientific researchScientific method
Scientific method refers to a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on gathering empirical and measurable evidence subject to specific principles of...
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 recognize this, the Astronomical Society of the Pacific
Astronomical Society of the Pacific
The Astronomical Society of the Pacific is a scientific and educational organization, founded in San Francisco on February 7, 1889. Its name derives from its origins on the Pacific Coast, but today it has members all over the country and the world...
annually gives 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 organizations, such as the American Association of Variable Star Observers
American Association of Variable Star Observers
Since its founding in 1911, the American Association of Variable Star Observers has coordinated, collected, evaluated, analyzed, published, and archived variable star observations made largely by amateur astronomers and makes the records available to professional astronomers, researchers, and...
and 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
Variable star
A star is classified as variable if its apparent magnitude as seen from Earth changes over time, whether the changes are due to variations in the star's actual luminosity, or to variations in the amount of the star's light that is blocked from reaching Earth...
s and supernovae, helping to track asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
s, and observing occultation
Occultation
An occultation is an event that occurs when one object is hidden by another object that passes between it and the observer. The word is used in astronomy . It can also refer to any situation wherein an object in the foreground blocks from view an object in the background...
s to determine both the shape of asteroids and the shape of the terrain on the apparent edge of the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
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
Kreutz Sungrazers
The Kreutz Sungrazers are a family of sungrazing comets, characterized by orbits taking them extremely close to the Sun at perihelion. They are believed to be fragments of one large comet that broke up several centuries ago and are named for German astronomer Heinrich Kreutz, who first...
) 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
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
s. Recently however, funding of projects such as the Lincoln Near-Earth Asteroid Research
Linear
In mathematics, a linear map or function f is a function which satisfies the following two properties:* Additivity : f = f + f...
and Near Earth Asteroid Tracking
Near Earth Asteroid Tracking
Near-Earth Asteroid Tracking is a program run by NASA and Jet Propulsion Laboratory to discover near-Earth objects. The NEAT project began in December 1995 and ran until April 2007.-History:...
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 societiesAstronomical society
There are numerous groups devoted to promoting astronomy research and education. See, for example:* Amateur Astronomers Association Delhi * Amateur Astronomers Association of New York * Amateur Astronomers Association of Pittsburgh...
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 simply be 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
Light pollution
Light pollution, also known as photopollution or luminous pollution, is excessive or obtrusive artificial light.The International Dark-Sky Association defines light pollution as:...
.
It is common for local societies to hold regular meetings, which may include activities such as star parties
Star party
A star party is a gathering of amateur astronomers for the purpose of observing the sky. Local star parties may be one night affairs, but larger events can last up to a week or longer and attract hundreds or even thousands of participants. Many regional star parties are now held annually and are an...
or presentations. Societies are also a meeting point for people with particular interests, such as amateur telescope making
Amateur telescope making
Amateur telescope making is the activity of building telescopes as a hobby, as opposed to being a paid professional. Amateur telescope makers build their instruments for personal enjoyment of a technical challenge, as a way to obtain an inexpensive or personally customized telescope, or as a...
.
Notable amateur astronomers
- George AlcockGeorge AlcockGeorge Eric Deacon Alcock was an English astronomer. He was one of the most successful visual discoverers of novae and comets....
, discoverer of comets and novae. - Thomas BoppThomas BoppThomas J. Bopp D.Sc is best known as co-discoverer of Comet Hale-Bopp in 1995. He was a manager at a construction materials factory and an amateur astronomer at the time of the comet discovery. It was the first comet he had observed....
, shared the discovery of Comet Hale-BoppComet Hale-BoppComet Hale–Bopp was perhaps the most widely observed comet of the 20th century, and one of the brightest seen for many decades...
in 1995 with unemployed PhD physicist Alan HaleAlan Hale (astronomer)-Biography:Hale was born in Tachikawa, Japan in 1958, but he grew up in Alamogordo, New Mexico. He served in the United States Navy from 1976 to 1983, graduating from the U.S. Naval Academy in 1980. His next job was at the Jet Propulsion Laboratory where he worked until 1986. While at the JPL, he...
. - Robert Burnham, Jr.Robert Burnham, Jr.Robert Burnham, Jr. was an American astronomer. He is best known for writing the classic three-volume Burnham's Celestial Handbook.-Early work:...
, author of the Celestial Handbook. - Andrew Ainslie CommonAndrew Ainslie CommonAndrew Ainslie Common FRS was an English amateur astronomer best known for his pioneering work in astrophotography.-Biography:...
(1841–1903), built his own very large reflecting telescopes and demonstrated that photography could record astronomical features invisible to the human eye. - Robert E. CoxRobert E. Cox-Career:Cox worked briefly at Perkin Elmer in 1939. Shortly thereafter he was inducted into the Army Air Corps and served for two years in the South Pacific as a weather specialist. After the war, Cox accepted part-time positions as photographic technician at Harvard Observatory and as staff...
(1917–1989) who conducted the "Gleanings for ATMs" column in Sky and Telescope magazine for 21 years. - John Dobson (1915), whose name is associated with the Dobsonian telescopeDobsonian telescopeA Dobsonian telescope is an alt-azimuth mounted newtonian telescope design popularized by the amateur astronomer John Dobson starting in the 1960s. Dobson's telescopes featured a simplified mechanical design that was easy to manufacture from readily available components to create a large, portable,...
, a simplified design for Newtonian reflecting telescopesNewtonian telescopeThe Newtonian telescope is a type of reflecting telescope invented by the British scientist Sir Isaac Newton , using a concave primary mirror and a flat diagonal secondary mirror. Newton’s first reflecting telescope was completed in 1668 and is the earliest known functional reflecting telescope...
. - Robert Owen EvansRobert 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 ....
is a minister of the Uniting Church in AustraliaUniting Church in AustraliaThe Uniting Church in Australia was formed on 22 June 1977 when many congregations of the Methodist Church of Australasia, the Presbyterian Church of Australia and the Congregational Union of Australia came together under the Basis of Union....
and an amateur astronomer who holds the all-time record for visual discoveries of supernovae. - Clinton B. FordClinton B. FordClinton B. Ford , aged 79, was an American investor, musician and amateur astronomer specializing in the observation of variable stars.- Birth and Family :...
(1913–1992), who specialized in the observation of variable stars. - Will HayWill HayWilliam Thomson "Will" Hay was an English comedian, actor, film director and amateur astronomer.-Early life:He was born in Stockton-on-Tees, in north east England, to William R...
, the famous comedian and actor, who discovered a white spot on Saturn. - Walter Scott HoustonWalter Scott HoustonWalter Scott Houston was an American popularizer of amateur astronomy. He wrote the "Deep-Sky Wonders" column in Sky and Telescope magazine from 1946 to 1993.-Biography:...
(1912–1993) who wrote the "Deep-Sky Wonders" column in Sky & TelescopeSky & TelescopeSky & Telescope is a monthly American magazine covering all aspects of amateur astronomy, including the following:*current events in astronomy and space exploration;*events in the amateur astronomy community;...
magazine for almost 50 years. - Albert G. IngallsAlbert Graham IngallsAlbert Graham Ingalls was an American scientific editor and amateur astronomer. Through his columns in Scientific American, including "The Amateur Scientist", and his three-volume series Amateur Telescope Making, Ingalls exerted a great influence on amateur astronomy and amateur telescope making...
(1888–1958), editor of Amateur Telescope Making, Vols. 1–3 and "The Amateur ScientistThe Amateur ScientistThe Amateur Scientist was a column in the Scientific American, and was the definitive "how-to" resource for citizen-scientists for over 72 years , making it the longest running column in Scientific American's history...
". He and Russell PorterRussell W. PorterRussell Williams Porter was an American artist, engineer, amateur astronomer and explorer. He was a pioneer in the field of “cutaway illustration" and is sometimes referred to as the "founder" or one of the "founders" of amateur telescope making."-Biography:Russell W...
are generally credited with having initiated the amateur telescope making movement in the US. - David H. LevyDavid H. LevyDavid H. Levy is a Canadian astronomer and science writer most famous for his co-discovery in 1993 of Comet Shoemaker–Levy 9, which collided with the planet Jupiter in 1994.-Biography:...
discovered or co-discovered 22 comets including Comet Shoemaker-Levy 9Comet Shoemaker-Levy 9Comet Shoemaker–Levy 9 was a comet that broke apart and collided with Jupiter in July 1994, providing the first direct observation of an extraterrestrial collision of solar system objects. This generated a large amount of coverage in the popular media, and the comet was closely observed by...
, the most for any individual. - Sir Patrick MoorePatrick MooreSir Patrick Alfred Caldwell-Moore, CBE, FRS, FRAS is a British amateur astronomer who has attained prominent status in astronomy as a writer, researcher, radio commentator and television presenter of the subject, and who is credited as having done more than any other person to raise the profile of...
, presenter of the BBC's long-running The Sky at NightThe Sky at NightThe Sky at Night is a monthly documentary television programme on astronomy produced by the BBC. The show has had the same permanent presenter, Sir Patrick Moore, from its first airing on 24 April 1957, making it the longest-running programme with the same presenter in television history.The...
and author of many books on astronomy. - Leslie PeltierLeslie PeltierLeslie Copus Peltier was an American astronomer.He was born in Delphos, Ohio. An amateur astronomer, he was a prolific discoverer of comets and also a persistent observer of variable stars and member of the AAVSO...
was a prolific discoverer of comets and well-known observer of variable stars. - John M. PierceJohn M. PierceJohn M. Pierce was an American teacher and amateur astronomer.Pierce worked with Russell W. Porter to organize Stellafane, the observatory near Springfield, Vermont where amateur telescope makers still meet annually for the Stellafane convention...
(1886–1958) was one of the founders of the Springfield Telescope Makers. In the 1930s he published a series of 14 articles on telescope making in Hugo GernsbackHugo GernsbackHugo Gernsback , born Hugo Gernsbacher, was a Luxembourgian American inventor, writer, editor, and magazine publisher, best remembered for publications that included the first science fiction magazine. His contributions to the genre as publisher were so significant that, along with H. G...
's "Everyday Science and Mechanics" called "Hobbygraphs". He is considered one of "the big three behind the amateur telescope making movement in America". - Tim Puckett, the principal investigator of the Puckett Observatory World Supernova Search team, which has discovered over 200 supernovae since 1998.
- Russell W. PorterRussell W. PorterRussell Williams Porter was an American artist, engineer, amateur astronomer and explorer. He was a pioneer in the field of “cutaway illustration" and is sometimes referred to as the "founder" or one of the "founders" of amateur telescope making."-Biography:Russell W...
founded StellafaneStellafaneStellafane is the name of the clubhouse built by the Springfield Telescope Makers club of Springfield, Vermont in the early 1920s, and has since come to refer to the club's land and buildings on the summit of Breezy Hill...
and has been referred to as the "founder" or one of the "founders" of amateur telescope makingAmateur telescope makingAmateur telescope making is the activity of building telescopes as a hobby, as opposed to being a paid professional. Amateur telescope makers build their instruments for personal enjoyment of a technical challenge, as a way to obtain an inexpensive or personally customized telescope, or as a...
. Albert G. IngallsAlbert Graham IngallsAlbert Graham Ingalls was an American scientific editor and amateur astronomer. Through his columns in Scientific American, including "The Amateur Scientist", and his three-volume series Amateur Telescope Making, Ingalls exerted a great influence on amateur astronomy and amateur telescope making...
is sometime given credit as co-founder of this movement. - Isaac RobertsIsaac RobertsIsaac Roberts was a Welsh engineer and business man best known for his work as an amateur astronomer, pioneering the field of astrophotography of nebulae. He was a member of the Liverpool Astronomical Society in England and was a fellow of the Royal Geological Society...
, early experimenter in astronomical photography. - Grote ReberGrote ReberGrote Reber was an amateur astronomer and pioneer of radio astronomy. He was instrumental in investigating and extending Karl Jansky's pioneering work, and conducted the first sky survey in the radio frequencies...
(1911–2002), pioneer of radio astronomyRadio astronomyRadio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The initial detection of radio waves from an astronomical object was made in the 1930s, when Karl Jansky observed radiation coming from the Milky Way. Subsequent observations have identified a number of...
constructing the first purpose built radio telescopeRadio telescopeA radio telescope is a form of directional radio antenna used in radio astronomy. The same types of antennas are also used in tracking and collecting data from satellites and space probes...
and conducted the first sky survey in the radio frequency.
Prizes recognizing amateur astronomers
- Amateur Achievement Award of Astronomical Society of the Pacific
- Astronomical League AwardAstronomical LeagueThe Astronomical League is an umbrella organization of amateur astronomy societies. Currently their membership consists of over 240 organizations across the United States, along with a number of Members-at-Large, Patrons, and Supporting members....
- Blair Medal of the Western Amateur Astronomers
- Chambliss Amateur Achievement AwardChambliss Amateur Achievement AwardThe Chambliss Amateur Achievement Award is awarded by the American Astronomical Society for an achievement in astronomical research made by an amateur astronomer resident in North America. The prize is named after Carlson R. Chambliss of Kutztown University, who donated the funds to support the prize...
See also
- Astronomical objectAstronomical objectAstronomical objects or celestial objects are naturally occurring physical entities, associations or structures that current science has demonstrated to exist in the observable universe. The term astronomical object is sometimes used interchangeably with astronomical body...
- ObservationObservationObservation is either an activity of a living being, such as a human, consisting of receiving knowledge of the outside world through the senses, or the recording of data using scientific instruments. The term may also refer to any data collected during this activity...
- Observational astronomyObservational astronomyObservational astronomy is a division of the astronomical science that is concerned with getting data, in contrast with theoretical astrophysics which is mainly concerned with finding out the measurable implications of physical models...
- Sidewalk astronomySidewalk astronomySidewalk or Street Corner Astronomy refers to the activity of setting up a telescope in an urban setting on a for profit or non-profit basis as an entertainment or for public education.-Overview:...
- Skygazing
- Star partyStar partyA star party is a gathering of amateur astronomers for the purpose of observing the sky. Local star parties may be one night affairs, but larger events can last up to a week or longer and attract hundreds or even thousands of participants. Many regional star parties are now held annually and are an...
- Clear Sky ChartClear Sky ChartClear Sky Charts are web graphics which deliver weather forecasts designed specifically for astronomers.They forecast the cloud cover, transparency and astronomical seeing, parameters which are not forecast by civil or aviation forecasts. They forecast hourly data, but are limited to forecasting...
Weather forecasts designed for amateur astronomers.
Amateur astronomy organizations
- American Association of Variable Star ObserversAmerican Association of Variable Star ObserversSince its founding in 1911, the American Association of Variable Star Observers has coordinated, collected, evaluated, analyzed, published, and archived variable star observations made largely by amateur astronomers and makes the records available to professional astronomers, researchers, and...
- Association of Lunar and Planetary ObserversAssociation of Lunar and Planetary ObserversThe Association of Lunar and Planetary Observers is an international scientific and educational organization established in March, 1947 in the United States by Walter H. Haas, and later incorporated in 1990...
- Astronomical LeagueAstronomical LeagueThe Astronomical League is an umbrella organization of amateur astronomy societies. Currently their membership consists of over 240 organizations across the United States, along with a number of Members-at-Large, Patrons, and Supporting members....
- British Astronomical AssociationBritish Astronomical AssociationThe British Astronomical Association is the senior national association of amateur astronomers in the UK.-Function:It encourages observational astronomy by non-professionals in areas which cannot be covered by professional observatories...
- Confederation of Indian Amateur Astronomer AssociationConfederation of Indian Amateur Astronomer AssociationThe Confederation of Indian Amateur Astronomers is a national level organisation of amateur astronomers in India that convenes a national meeting of members every year, and coordinates the activities of amateur astronomers throughout the country...
(India) - Khagol vishwaKhagol VishwaKhagol Vishwa is an organization for amateur astronomers working in Pune and Pimpri - Chinchwad Area, India. It was established on 17th Nov. 1999, under Society Registration Act, 1960...
(India) - Khagol MandalKhagol MandalKhagol Mandal is an organization of amateur astronomers in Mumbai, India. Established in 1985 by handful of astronomy enthusiasts, the organization has grown into a membership of 1000+ within past 24 years. Khagol Mandal completed 25 years in 2009...
(Mumbai, India) - Society for Popular AstronomySociety for Popular AstronomyThe Society for Popular Astronomy is a national astronomical society based in the United Kingdom for beginners to amateur astronomy.It was founded in 1953 as the Junior Astronomical Society by experienced amateur astronomers including Patrick Moore, Ernest Noon and Eric Turner to encourage...
(UK) - Royal Astronomical Society of CanadaRoyal Astronomical Society of CanadaThe Royal Astronomical Society of Canada is a national, non-profit, charitable organization devoted to the advancement of astronomy and related sciences. At present, there are 29 local branches of the Society, called centres, located in towns and cities across the country from St. John's,...
- Federation of Astronomical SocietiesFederation of Astronomical SocietiesThe Federation of Astronomical Societies is an international union of astronomical societies formed in 1974. FAS publishes a newsletter 3 times a year, which is sent to its member societies, and holds an annual convention. FAS is run by a council of elected volunteers.-External links:* *...
(UK) - SAJ Vidnyan (Raigad,Maharashtra)