June 6, 2020

The Contributions of Amateur Astronomers to Modern Science

(Author’s note; the essay below was a paper submitted recently by yours truly as part of my quest for a bachelors degree in science teaching. I’ve posted it here pretty much intact. Some explanations on the graphs have been expanded; I thought it was a shame for all of my research on the subject to go to waste. The bibliography is also included.)

Today, the modern science of astronomy is growing like never before. New technologies are opening up unseen vistas scarcely imagined just twenty years ago. Amateur astronomers are continuing to provide useful scientific data in the modern age of high technology by adapting to a changing observational environment. Webster’s Dictionary (Berube, 1985), defines an amateur as “A person who engages in an art, science, study or athletic activity as a pastime rather than as a profession.” It is true, many who practice the science of astronomy recoil at the thought of being called amateurs. Others may even resort to the more action packed term “visual athletes”. While an amateur can stand for a skilled enthusiast, it can also denote a novice. Some astronomers may even have such a breadth of expertise so as to overlap both definitions.
Astronomy may well be one of the oldest of the natural sciences. From the beginning of recorded history, humans have worked to settle their place in the universe. Some of the oldest known texts were astronomical in nature. Babylonian records of a lunar eclipse date from 721 B.C. (Weigert, A. & Zimmermann, H. pg. 34). Early astronomers found employment primarily as forecasters of horoscopes. This continued right up until Kepler’s time, when he maintained a meager existence casting horoscopes while pursuing serious studies. With the reform of the western calendar to the Gregorian in the 16th century came a need to know precise dates, namely the timings for Easter holiday. Astronomers once again found secular employment.
During this period, no true distinction between amateur and professional astronomers existed. Most men of science either subsisted via other means, such as medicine or mathematics, or dabbled in astronomy as a side. Most rulers were content with the funding of wars, and held an Aristotelian view that the heavens were unchanging and therefore, unknowable.
Two men changed all that and could be properly called the fathers of modern astronomy; Galileo and Isaac Newton. Contrary to popular belief, Galileo did not event the telescope; he merely was the first to turn it towards the stars. Unbiased, he simply documented what he saw. True observational astronomy was born. Soon after, Isaac Newton single handedly vaulted physics decades, if not centuries ahead. Among his notable achievements were the invention of the reflecting telescope and the detection of the spectrum, but his theories of motion and gravity were the most crucial. For the first time, the position of an orbiting object could be predicted with great accuracy. Theoretical astronomy was born.
Then, on the night of March 13, 1781, a serendipitous discovery was made. Scanning the sky near the Crab Nebula, astronomer William Hershel came across a particular nebulous star that refused to focus (Baum & Sheehan, 1997). Herschel discovered what he at first believed to be a comet; in time, it was realized to be a new planet, the first one to be added since classical times. His native England was flushed with national pride; for a time, the new planet was even referred to as “George”! However, the rest of the world began to use the term “Uranus”. Observational astronomy was once again in business.
Soon, it became apparent that there were problems with the new planet; namely, it wasn’t moving as predicted by the new Newtonian laws. These could only be made sense of if an unseen object were tugging at Uranus. In a daft stroke, a French mathematician by the name of Le Verrier, made a daring prediction; aim your telescope at a predicted patch of sky on a particular date, he claimed, and a new planet would be discovered (Bakich, 2003 pg 211). On September 23, 1847, Neptune was spotted by an observatory in Berlin. This time, France enjoyed the national prestige and for the first time, an astronomical object was located purely by prediction. The divergence of amateur and professional astronomy was underway.
To be sure, astronomy as a vocation had traditionally always been the game of the very rich. Mass marketing of astronomical equipment did not appear until after the Second World War. You either had the private funds available to purchase a high end, hand crafted instrument or had the knowledge and means to build your own. The proliferation of technology has resulted in mass access to astronomy. The advent of modern astronomy has also given birth to whole new realms of research in which amateurs now contribute.
In the field of variable stars, amateurs until very recently provided all the data accumulated. Using little more than hand drawn charts, they patiently observe a given star night after night, comparing its brightness against known stars nearby. Some skilled observers, such as the legendary variable observer George Alcock, can have sensitivity as low as a tenth of a magnitude, a variation that would go unnoticed by the casual observer (North, 1997, pg 289). Variables of importance to astrophysics include a class known as Cepheid’s, a “standard candle” that serves as a yardstick to measure intergalactic distance. Modern observers now employ CCD cameras and imaging software to record hundreds of variables a night.
Perhaps no facet of astronomy is as romantic as comet hunting. Every clear night, legions of dedicated observers sweep the dawn or dusk skies searching for these cosmic interlopers. Some spend decades before their first catch. But the prize is rewarding; a discovery can mean joining an elite few who have had their name immortalized by a celestial body. The skills gained through years of endless searching are also a testimony to the discipline required.

The graph below was compiled by the author. It breaks down comet discoveries by year over the last quarter century into three catagories; amateur, professional, and automated discoveries. Please note that the definitions of “amateur” and “professional” are only approximate; some individuals blur the line between the two. Many comets also have more than one discoverer; current conventions allow for up to three. Some were discovered by a combination of catagories, such as IRAS-Araki-Alcock, which was independently discovered by both an automated survey and an amateur astronomer.

Two interesting facts can be drawn from the compiled data above; one is that the raw number of comet discoveries has definitely taken off since the initiation of the SOHO and LINEAR programs in 1996. Interesting fact number two is that dispite amateur perceptions that automated surveys are “snatching up” discoveries, amateur discovery numbers remain basically unchanged!

In contrast, no skill is more unknown or arcane than occultation timing. When one object passes in front of another, most commonly the moon or an asteroid in front of a star or planet, it is known as an occultation. If the time the star winks in and out can be precisely recorded, a cross section of the asteroid or lunar limb can be plotted. This single observation is known as a chord. If enough observers can be positioned strategically along a line, a profile of the asteroid or lunar limb can be deduced, albeit indirectly. Companions, or twin asteroids, have been discovered in this fashion. For example, the hidden companion of asteroid 90 Antiope was revealed during a series of mutual eclipses in May of 2005 (Staff writers, Space Daily 2007).

The field meteor shower observing has almost entirely been pioneered by amateurs. It requires only low tech effort; no telescope or specialized equipment is needed. All that is necessary is patience, a recording method such as pen and pad or a recorder, and a good knowledge of the sky. If enough showers are observed over a period of time, the path of a meteor stream and its parent body, usually a comet or sometimes an asteroid can be deduced. The collection of meteorites has even led to fame and notoriety for some, such as meteorite dealer Robert Haag (Shubinski, R, 84-87).
Novae and supernovae discoveries have also been occasionally made by amateurs. Sometimes inadvertently, a skilled observer may spot something out of place while casually observing. More often, the discoveries are a result years of patient study. Observers will frequently memorize entire star charts down to a certain magnitude. Curiously, no naked eye supernovae have been spotted since pre-telescopic times (Warner, 2006). Our galaxy is long overdue. Type 1A supernovae explode in a predictable fashion and can also serve as standard “yardsticks” to measure cosmological distances. Novae can be considered as a sub-discipline of variables in that several cataclysmic variables eventually do go nova.
One of the most valuable services an amateur can provide is the discovery and tracking of Near Earth Objects (NEOs). Primarily asteroids, these objects range from the size of a school bus to a large mountain. If their orbit intersects that of the earth, they can pose a hazard. The immediate danger may be local, causing forest fires or tsunamis, or classed as an extinction level event. These hazards have only recently been realized, and a minuscule amount of professional “telescope time” is spent on this effort. By meticulously examining successive exposures, amateurs routinely discover asteroids drifting silently through the solar system (North, 1997 pg 221-222). Amateurs fill this critical gap by providing much needed data.
Some amateur efforts are truly on the cutting edge. Endeavors such as spectroscopy, or the examination of spectra, can give us information about a stars age, composition, and temperature (Tonkin, 2002). Follow up observations of gamma-ray bursts can swing large telescopes into action to pin point faint afterglows. Utilizing NASA’s fledgling burst alert system, amateurs such as South Africa’s Berto Monard have even beaten professionals to the punch (News Office MIT, 2003). Finally, there is the recent discovery of exo-planets, such as the one discovered by a collaboration of professionals and amateurs in late 2005 using a transit method in which the planet slightly dims its host star (Layton, 2007). This technique was solely the realm of professionals until only a few years ago. Astrophysicist Debra Fischer notes; “There aren’t enough professional astronomers to carry out the intense monitoring of stellar brightness that we need on all of our stars.” (Ferris, 2007). Again, amateurs routinely fill this void.
To be certain, the encroachment of high technology has had its pitfalls. As the role of the amateur goes the way of the professional, much of what is deemed as the romance of astronomy is lost. Gone are the days of the diligent lone astronomer peering into the eyepiece on a wind swept mountain top, stopwatch in one hand, pipe in the other ala Percival Lowell. According to Claude Plymate, an engineering physicist at the National Solar Observatory at Kitt Peak, Arizona and avid amateur astronomer, the role of the amateur may soon be regulated to sifting through mountains of data (interview, October 4, 2007). Meanwhile, professionals may routinely use results from robotic observatories that they’ve never seen. Already, automated observing programs, such as LINEAR, have given dedicated asteroid and comet chasers a run for their money. Comet hunter David Levy states (2007), “Its one thing for a long time comet hunter to continue a search program in an era when professional sky patrols make virtually all routine comet discoveries. It’s quite another for an amateur to begin a search program under these circumstances.” It’s now more likely a new comet discovered tomorrow will be named after a machine than a man.
Space probes also gain what might be deemed as an unfair advantage. Perched high above the earth’s murky atmosphere, these orbiting observatories like SOHO, Hubble, Chandra, and Spitzer have a superior vantage point and access to ends of the light spectrum undreamt of by earth based amateurs. Another negative impact of modern society is the intrusion of light pollution. Still very much outside the public consciousness, over a billion dollars are wasted each year needlessly illuminating the sky (Bakich, 2003). Modern day amateurs sometimes need to travel over one hundred miles from the suburbs to find pristine skies. Even professional observatories which are deemed a national investment and resource are not immune to the deleterious effects of light pollution. As an example, below is a light pollution map over northern Maine centered on the authors’ own Twin Dogs Observatory on Saint Froid Lake:

Public perceptions of amateur astronomers run the gamut. To the surprise of many, most professional astronomers no longer approach the field via observational practice. Most now come into the study of astronomy through mathematics or physics, as noted by C. Plymate (interview, October 4, 2007). Knowledge of observing basics is no longer a requirement. Many are surprised by the simple, low tech paths that can be used to achieve scientific data. Much of these false interpretations are reflected in modern media (Plait, 2007). Observing things like aurora, satellites, and meteors require no equipment at all; here the parity between amateurs and professionals is striking.
Some professionals even started as amateurs; others blur the line between the two. Clyde Tombaugh, the discoverer of Pluto, built his own reflecting telescope while still a teenager. Australian minister Robert Owen Evans has independently discovered 40 supernovae, an all time record (Kamenicek, 2007). Avid amateur David Levy has independently discovered several comets, including Shoemaker-Levy 9 which crashed into Jupiter. He continues his vigil from his backyard observatory in Vail, Arizona.
Several innovations in amateur astronomy have been achieved in the last few decades. One is the development of digital imaging. CCD (Charged Coupled Devices), image stacking and processing, and robotic technology have proved to be a boon for amateurs. Larger and faster computing power also means that events such as asteroid occultations can now be computed with astonishing accuracy and almost routine frequency. Collaborations between amateur group and professionals have also reached fruition, such as a Montreal based group gaining access to the Gemini telescope to resolve dust formations surrounding the infant star RY Tauri (Berman, 2005). The World Wide Web has enabled faster communication, resulting in astronomical information and alerts being flashed around the globe in a matter of seconds.
Future trends may include more automation, more powerful optics, and access to large scientific databases. Although there will most likely always be observing purists, the future amateur astronomer may, like his current professional counterpart, observe purely from the desktop. Technology has reached a point where scientific data can be gathered by individuals remotely (Ferris, 2007). There have already been some preliminary steps toward this trend. Programs known as distributed computing allow owners to utilize their idle processing power to participate in the search for gravity waves, cometary debris, and alien intelligence. Some amateurs have even discovered comets by sifting through images taken by the Solar Heliocentric Observatory (SOHO) satellite as it monitors the sun (European Space Agency, 2007). For those with cloudy skies, access to automated telescopes and virtual archives are now available. It is certain that as the computer revolution progresses at an exponential rate, new and unthought-of applications will present themselves.
In conclusion, the ability of amateur astronomers to provide useful scientific data in the high tech era continues to be valid. Although the roles of both professional and amateur may have changed, the need for keen-eyed observers still remains in many diverse sub-disciplines. While some see it as a “technological arms race”, others believe technology may ultimately be a great equalizer and enabler. In time, the advent of “virtual observing” will put new discoveries in the reach of a keystroke. I, for one, will never tire of the solitude and sense of perspective I get standing alone under a truly dark sky. But I also love to tinker and see what’s coming down the road. With any luck, it’s a collaboration that will never end!

Below is a selection of innovative amateur observatory designs:

I once constructed a simple “pull off roof” observatory in three days while living in in Vail, Arizona. It was simply a modified 9x10ft Sears’ shed built to house a 10″ Schmidt-Newtonian. It cost less than 500$ US to build.

Don’t be afraid of unconventional designs. Their are two main goals of an observatory; it keeps the scope sheltered while at the same time, its ready to go at a moments notice!A dome observatory has that “classic” look… it also shelters the scope from vibrations caused by high winds. A possible downside is that they can also “trap in seeing” and turbulence.

And finally, a robotic observatory. Some guys have a sports car for their mid-life crisis; this could be mine!

A link to the video presentation can be found at;


Bakich, M. (2003). The Cambridge encyclopedia of amateur astronomy (pp. 34-35). New York, NY: Cambridge University Press.
Baum, R. & Sheehan, W. (1997). In search of planet Vulcan (pp. 48-49).Cambridge, MA:
Basic Books.
Berman, R. (2005 August). Amateurs explore stellar cocoon. Astronomy online. Retrieved September 26, 2007 from the WGU Library. http://tinyurl.com/3ajhxx
Berube, M. (Ed.) (1985). Amateur definition. In American heritage dictionary (2nd ed.), Boston, MA: Houghton Mifflin Company.
European Space Agency. (2007). 1000th Kreutz sungrazing comet discovered by SOHO. Retrieved October 21, 2007, from the World Wide Web: http://www.esa.int/esaSC/SEMQ0AJZBQE_index_0.html
Ferris, T. (2007 September). Seeing in the dark. PBS video documentary.
Kamenicek, J. (2007 September). Robert Evans (astronomer). Wikipedia.org. Retrieved October 10, 2007 from the World Wide Web: http://en.wikipedia.org/wiki/Robert_Evans_%28astronomer%29
Levy, D. Tales of two comets. Sky & Telescope. October 2007, 82-83.
Layton, L. (2006 September). Low-tech path to an Exoplanet. Astronomy online. Retrieved September 26, 2007 from the WGU Library. http://tinyurl.com/2qzrzm
News Office MIT. (2003 August). Amateur locates powerful stellar explosion before the pros.
Retrieved September 27, 2007 from the World Wide Web: http://web.mit.edu/newsoffice/2003/grb.html
North, G. (1997). Advanced Amateur Astronomy. 2nd ed (pp. 221, 289). New York, NY: Cambridge University Press.
Plait, P. (2007 October). Misconceptions. Bad astronomy.com. Retrieved October 11, 2007 from the World Wide Web: http://www.badastronomy.com/bad/misc/index.html
Shubinski, R. Rock star. Astronomy magazine. August 2006, 84-87.
Staff Writers Space Daily. (2007 March). Amateur and professional astronomers combine observations to produce double asteroid image. Space daily.com. Retrieved September 27, 2007 from the World Wide Web: http://tinyurl.com/2qj22u
Tonkin, S. (2002). Practical amateur spectroscopy (pp. ix). London, United Kingdom:
Springer-Verlag London Limited.
Warner, B (2006 February). Where have all the novae gone?
Astronomy & Geophysics; Feb2006, Vol. 47 Issue 1, 2Novae abstract.
Weigert, A. & Zimmermann, H. (1975). Concise encyclopedia of astronomy (pp. 211, 251).
Translated from German by. J. Home Dickson. Adam Hilger: London.


  1. Diego Gray says:

    CCD cameras have very good quality but CMOS cameras are way cheaper:”

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