Amateur astronomy

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Amateur astronomers watch the night sky during the Perseid meteor shower. Astronomy Amateur 3 V2.jpg
Amateur astronomers watch the night sky during the Perseid meteor shower.

Amateur astronomy is a hobby where participants enjoy observing or imaging celestial objects in the sky using the unaided eye, binoculars, or telescopes. Even though scientific research may not be their primary goal, some amateur astronomers make contributions in doing citizen science, such as by monitoring variable stars, [1] double stars, [2] sunspots, [3] or occultations of stars by the Moon [4] or asteroids, [4] or by discovering transient astronomical events, such as comets, [5] galactic novae [6] or supernovae in other galaxies. [7]

Contents

Amateur astronomers do not use the field of astronomy as their primary source of income or support, and usually have no professional degree in astrophysics or advanced academic training in the subject. Most amateurs are hobbyists, while others have a high degree of experience in astronomy and may often assist and work alongside professional astronomers. [8] Many astronomers have studied the sky throughout history in an amateur framework; however, since the beginning of the twentieth century, professional astronomy has become an activity clearly distinguished from amateur astronomy and associated activities. [9]

Amateur astronomers typically view the sky at night, when most celestial objects and astronomical events are visible, but others observe during the daytime by viewing the Sun and solar eclipses. Some just look at the sky using nothing more than their eyes or binoculars, but more dedicated amateurs often use portable telescopes or telescopes situated in their private or club observatories. Amateurs also join amateur astronomical societies, which can advise, educate or guide them towards ways of finding and observing celestial objects. They also promote the science of astronomy among the general public. [10]

Objectives

Amateur astronomer recording observations of the sun. Hans Oberndorfer 2.JPG
Amateur astronomer recording observations of the sun.

Collectively, amateur astronomers observe a variety of celestial objects and phenomena. Common targets of amateur astronomers include the Sun, the Moon, planets, stars, comets, meteor showers, and a variety of deep sky objects such as star clusters, galaxies, and nebulae. 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 with the introduction of far easier to use equipment including, digital cameras, DSLR cameras and relatively sophisticated purpose built high quality CCD cameras and CMOS cameras.

Most amateur astronomers 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 filters on conventional telescopes, and also the use of radio telescopes. Some amateur astronomers use home-made radio telescopes, while others use radio telescopes that were originally built for astronomical research but have since been made available for use by amateurs. The One-Mile Telescope is one such example.

Common tools

Places like Paranal Observatory offer crystal clear skies for observing astronomical objects with or without instruments. Beneath the Milky Way.jpg
Places like Paranal Observatory offer crystal clear skies for observing astronomical objects with or without instruments.

Amateur astronomers use a range of instruments 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 optical telescopes of varying power and quality, as well as additional sophisticated equipment, such as cameras, to study light from the sky in both the visual and non-visual parts of the spectrum. To further improve studying the visual and non-visual part of the spectrum, amateur astronomers go to rural areas [12] to get away from light pollution. Commercial telescopes are available, new and used, but it is also common for amateur astronomers to build (or commission the building of) their own custom telescopes. 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. Recent models of iPhones have introduced a "night mode [13] " option when taking pictures as well, that allows you to increase exposure, which is a period of time the picture is being taken for. This optimizes focus on light in the frame which is why it is used primarily at night.

Amateur astronomers also use star charts that, depending on experience and intentions, may range from simple planispheres through to star atlases with detailed charts of the entire night sky. A range of astronomy software is also 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 information gathered is used to help studies and interactions between amateur astronomers in yearly gatherings. Although not professional information or credible, it is a way for the hobby lovers to share their new sightings and experiences.

The popularity of 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.

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. Although many methods are used in amateur astronomy, most are variations of a few specific techniques.[ according to whom? ]

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, 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 mounts with setting circles, which allow pointing to targets in the sky using celestial coordinates, and GOTO telescopes, which are fully automated telescopes that are capable of locating objects on demand (having first been calibrated).

Mobile apps

The advent of mobile applications for use in smartphones has led to the creation of many dedicated apps. [14] [15] These apps allow any user to easily locate celestial objects of interest by simply pointing the smartphone device in that direction in the sky. These apps make use of the inbuilt hardware in the phone, such as GPS location and gyroscope. Useful information about the pointed object like celestial coordinates, the name of the object, its constellation, etc. are provided for a quick reference. Some paid versions give more information. These apps are gradually getting into regular use during observing, for the alignment process of telescopes. [16]

Setting circles

Setting circles are angular measurement scales that can be placed on the two main rotation axes of some telescopes.[ citation needed ] 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 (i.e., point) 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 a celestial object in a telescope equipped with a DSC computer, one does not need to look up the specific RA and Dec coordinates in a book or other resource, and then adjust the telescope to those numerical readings. Rather, the object is chosen from the electronic database, which causes distance values and arrow markers to appear in the display that indicate the distance and direction to move the telescope. The telescope is moved until the two angular distance values reach zero, indicating that the telescope is properly aligned. When both the RA and Dec axes are thus "zeroed out", the object should be in the eyepiece. Many DSCs, like go-to systems, can also work in conjunction with laptop sky programs.[ citation needed ]

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. [17]

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 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-azimuth telescope mounts, allowing them to produce an overall less expensive product. GOTO telescopes usually have to be calibrated using alignment stars 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-controlled 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 great distance away in a dark location. The observer can image through the telescope 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 Bareket observatory, and there are telescope farms in New Mexico, [18] Australia and Atacama in Chile. [19]

Imaging techniques

An image of the Cat's Paw Nebula created combining the work of professional and amateur astronomers. The image is the combination of the 2.2-metre MPG/ESO telescope of the La Silla Observatory in Chile and a 0.4-meter amateur telescope. The Cat's Paw Remastered.jpeg
An image of the Cat's Paw Nebula created combining the work of professional and amateur astronomers. The image is the combination of the 2.2-metre MPG/ESO telescope of the La Silla Observatory in Chile and a 0.4-meter amateur telescope.

Amateur astronomers engage in many imaging techniques including film, DSLR, LRGB, 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. Narrowband filters may also be used to minimize light pollution.

Scientific research

Scientific research is most often not the main goal for many amateur astronomers, unlike professional astronomers. 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 the British Astronomical Association, exist to help coordinate these contributions.

Amateur astronomers often contribute toward activities such as monitoring the changes in brightness of variable stars and supernovae, helping to track asteroids, and observing occultations 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 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

Amateur astronomy groups are often involved in outreach to introduce astronomy to the general public Outreach, one of the most rewarding jobs (4798622790).jpg
Amateur astronomy groups are often involved in outreach to introduce astronomy to the general public

There are a large number of amateur astronomical societies around the world, that serve as a meeting point for those interested in amateur astronomy. Members range from active observers with their own equipment to "armchair astronomers" who are simply interested in the topic. Societies range widely in their goals and activities, which may depend on a variety of factors such as geographic spread, local circumstances, size, and membership. For example, a small local society located in dark countryside may focus on practical observing and star parties, whereas a large one based in a major city might have numerous members but be limited by light pollution and thus hold regular indoor meetings with guest speakers instead. Major national or international societies generally publish their own academic journal or newsletter, and some hold large multi-day meetings akin to a scientific conference or convention. They may also have sections devoted to particular topics, such as lunar observation or amateur telescope making.

Notable contributions by amateur astronomers

Sir Patrick Moore was one of the world's leading popularisers of astronomy. Sir Patrick Moore at the opening of the South Downs Planetarium.jpg
Sir Patrick Moore was one of the world's leading popularisers of astronomy.

There have been many significant scientific, technological, and cultural contributions made by amateur astronomers:

Citizen science projects

Amateur astronomers and other non-professionals make contributions through ongoing citizen science projects:

Prizes recognizing amateur astronomers

See also

Related Research Articles

<span class="mw-page-title-main">Astronomer</span> Scientist in the field of astronomy

An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, moons, comets and galaxies – in either observational or theoretical astronomy. Examples of topics or fields astronomers study include planetary science, solar astronomy, the origin or evolution of stars, or the formation of galaxies. A related but distinct subject is physical cosmology, which studies the Universe as a whole.

<span class="mw-page-title-main">Astrophotography</span> Imaging of astronomical objects

Astrophotography, also known as astronomical imaging, is the photography or imaging of astronomical objects, celestial events, or areas of the night sky. The first photograph of an astronomical object was taken in 1840, but it was not until the late 19th century that advances in technology allowed for detailed stellar photography. Besides being able to record the details of extended objects such as the Moon, Sun, and planets, modern astrophotography has the ability to image objects outside of the visible spectrum of the human eye such as dim stars, nebulae, and galaxies. This is accomplished through long time exposure as both film and digital cameras can accumulate and sum photons over long periods of time or using specialized optical filters which limit the photons to a certain wavelength.

<span class="mw-page-title-main">Photometry (astronomy)</span> Determination of light intensities of astronomical bodies

In astronomy, photometry, from Greek photo- ("light") and -metry ("measure"), is a technique used in astronomy that is concerned with measuring the flux or intensity of light radiated by astronomical objects. This light is measured through a telescope using a photometer, often made using electronic devices such as a CCD photometer or a photoelectric photometer that converts light into an electric current by the photoelectric effect. When calibrated against standard stars of known intensity and colour, photometers can measure the brightness or apparent magnitude of celestial objects.

<span class="mw-page-title-main">Star party</span>

A star party is a gathering of amateur astronomers for the purpose of observing objects and events in the sky. Local star parties may be one-night affairs, but larger events can last a week or longer and attract hundreds or even thousands of participants. Many astronomy clubs have monthly star parties during the warmer months. Large regional star parties are held annually and are an important part of the hobby of amateur astronomy. A naturally dark site away from light pollution is typical.

<span class="mw-page-title-main">Dobsonian telescope</span> Type of Newtonian telescope popularized by John Dobson

A Dobsonian telescope is an altazimuth-mounted Newtonian telescope design popularized by John Dobson in 1965 and credited with vastly increasing the size of telescopes available to amateur astronomers. Dobson's telescopes featured a simplified mechanical design that was easy to manufacture from readily available components to create a large, portable, low-cost telescope. The design is optimized for observing faint, deep-sky objects such as nebulae and galaxies. This type of observation requires a large objective diameter of relatively short focal length and portability for travel to less light-polluted locations.

<span class="mw-page-title-main">Observational astronomy</span> Division of astronomy

Observational astronomy is a division of astronomy that is concerned with recording data about the observable universe, in contrast with theoretical astronomy, which is mainly concerned with calculating the measurable implications of physical models. It is the practice and study of observing celestial objects with the use of telescopes and other astronomical instruments.

<span class="mw-page-title-main">Deep-sky object</span> Any astronomical object that is not an individual star

A deep-sky object (DSO) is any astronomical object that is not an individual star or Solar System object. The classification is used for the most part by amateur astronomers to denote visually observed faint naked eye and telescopic objects such as star clusters, nebulae and galaxies. This distinction is practical and technical, implying a variety of instruments and techniques appropriate to observation, and does not distinguish the nature of the object itself.

<span class="mw-page-title-main">Robotic telescope</span>

A robotic telescope is an astronomical telescope and detector system that makes observations without the intervention of a human. In astronomical disciplines, a telescope qualifies as robotic if it makes those observations without being operated by a human, even if a human has to initiate the observations at the beginning of the night or end them in the morning. It may have software agents using artificial intelligence that assist in various ways such as automatic scheduling. A robotic telescope is distinct from a remote telescope, though an instrument can be both robotic and remote.

A small telescope is generally considered by professional astronomers to be any reflecting telescope with a primary mirror that is less than 2 metres (80 in) in diameter. By amateur standards, a small telescope can have a primary mirror/aperture less than 6–10 inches (150–250 mm) in diameter. Little if any professional-level research is performed with refracting telescopes in the modern era of astronomy.

Video astronomy(aka - Camera Assisted Astronomy, aka electronically-assisted astronomy or "EAA") is a branch of astronomy for near real-time observing of relatively faint astronomical objects using very sensitive CCD or CMOS cameras. Unlike lucky imaging, video astronomy does not discard unwanted frames, and image corrections such as dark subtraction are often not applied, however, the gathered data may be retained and processed in more traditional ways.. Although the field has a long history reaching back to 1928 with the inception of live television broadcasting of the planet Mars, it has largely been developed more recently by amateur enthusiasts and is characterized by the use of relatively inexpensive equipment, such as easily available sensitive security cameras, in contrast to the equipment used for advanced astrophotography.

<span class="mw-page-title-main">Astrograph</span> Type of telescope

An astrograph is a telescope designed for the sole purpose of astrophotography. Astrographs are mostly used in wide-field astronomical surveys of the sky and for detection of objects such as asteroids, meteors, and comets.

<i>Astronomy</i> (magazine)

Astronomy is a monthly American magazine about astronomy. Targeting amateur astronomers, it contains columns on sky viewing, reader-submitted astrophotographs, and articles on astronomy and astrophysics for general readers.

<span class="mw-page-title-main">Visible-light astronomy</span> Encompasses a wide variety of astronomical observation via telescopes

Visible-light astronomy encompasses a wide variety of astronomical observation via telescopes that are sensitive in the range of visible light. Visible-light astronomy is part of optical astronomy, and differs from astronomies based on invisible types of light in the electromagnetic radiation spectrum, such as radio waves, infrared waves, ultraviolet waves, X-ray waves and gamma-ray waves. Visible light ranges from 380 to 750 nanometers in wavelength.

John "Jack" Borden Newton is a Canadian astronomer, best known for his publications and images in amateur astrophotography.

<span class="mw-page-title-main">Nik Szymanek</span> British astronomer

Nicholas Szymanek, better known as Nik Szymanek, is a British amateur astronomer and prolific astrophotographer, based in Essex, England.

Steve Mandel is an amateur astronomer and astrophotographer. He owns a small observatory, called Hidden Valley Observatory, in Soquel, California. He has been acknowledged especially for his wide-field photographs of the Milky Way nebulae and for public outreach, for which he has received Amateur Achievement Award of the Astronomical Society of the Pacific. Besides this he has also captured and published wildlife images of endangered animals. He works as an American communications coach for professional executives, and is the founder of the Mandel Communications Inc., which aims to teach effective communication and public speaking.

<span class="mw-page-title-main">Astronomical Society of New South Wales</span> Amateur astronomy club in the state of New South Wales, Australia

The Astronomical Society of New South Wales (ASNSW) is an amateur astronomy club in the state of New South Wales, Australia, founded in 1954.

<span class="mw-page-title-main">Howard J. Brewington</span> American astronomer (born 1952)

Howard J. Brewington is an American comet discoverer and former professional telescope operator of the Sloan Digital Sky Survey.

<span class="mw-page-title-main">Steve Gottlieb (amateur astronomer)</span>

Steven Michael Gottlieb is an American amateur astronomer, researcher, writer and lecturer.

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Further reading