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Who Is The Greatest Visual Observer Of All Time?

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SXN's picture
Who Is The Greatest Visual Observer Of All Time?

The case can be made for several people.

In the US, we might say Leslie Peltier. Our friends down under would probably say Albert Jones. The Brits could make a case for George Alcock. And Daniel Overbeek belongs somewhere in this discussion.

So, what are your thoughts?

Can you make a case for one over the other based on anything other than where you live?

Is there anyone else who belongs in this conversation?

KTC's picture
Dmitry Maksutov - master of the human eye

Dmitry Maksutov.

Don't bother looking for visual observer totals in AAVSO.  That's not what made him great.

He studied and mastered the workings of the human eye.

It was a revelation to translate his two books on telescope making.  One section deals with the he studied it...and what he learned.  Considering that his studies were done in the Soviet Union in the 1920's, 30's and 40's...his results were impressive.

Among other things he made artificial double stars to test the eye's resolution...under a wide range of brightness levels, difference in brightness between the two artificial stars, and pupil sizes.

From that, he determined the various factors that limited the eye's resolution...including the 'pixelation limit' imposed by the density/spacing of the light sensitive cells in the retina...and his findings are in good agreement with modern data.  See attached graphic from Maksutov's first book.

He also 'star tested' his own eyes.  See attached drawing.

He also studied the eye's contrast sensitivity to extended, faint, low contrast objects...crucial information for optimal viewing of planets and nebulae.

And that part of the book ends with a plea for more testing/info from other astronomers.

It’s especially important to know how to apply the theory discussed above when designing new optical instruments: consumer, military, geodetic, etc., so that they are equipped with the best eyepieces for their given observing tasks.

But we are powerless to give any strict guidelines until there appears statistically reliable material on the resolving power, aberrations, and inhomogeneities of the average observer’s eye.

Therefore I must repeat my appeal from 19 years ago to astronomers, who are most able to undertake such studies: “test your eyes’ performance and report to the author your objective and thorough findings!”

How many visual observers today test the performance of their eyes?

PYG's picture
Greatest visual observer

For me there is no doubt - George Alcock.  Not couning his five Novae and five Comets, he produced lists and lists of stars missing from the common atlas's of the day - SAO,  Boralis, Eclipticalis etc. (I still own copies). All from memory.  He remembered the positions and magnitudes of +40,000 stars to below magnitude 8.0 along the Milky Way and other area's of the sky, which helped in his Nova searches and Meteor work.  Lets also remember that George didn't even use a telescope!  He was a meticulous observer of the night sky - and day, making weather observations from his home in Peterborough and whilst he was serving in the army during the war.  

I don't know of many observers who might possibly detect the position of Cere's at +6.5 magnitude naked eye and, unaware of what he was seeing (until he called his friend Roy Panther - of Comet Panther fame), knew instantly that he had an interloper.  It makes the mind boggle - well mine anyway.

There have been many fine observers of the night sky (we aren't just talking variables here), and it almost seems disrespectful to name one as the most outstanding - but I have, and I won't be convinced otherwise!  We'll never see the like again!

Gary (PYG)

PKV's picture
I vote for Albert Jones

I vote for Albert Jones.  His 465,873 observations over 68.61 years speaks volumes.  This equates to an average 6,790 observations per year!  And all of this was done with a manual non-goto mount. His contributions in the southern sky have tremedously helped in our understanding of many important variable stars "down under." 

The "interbiew" tells much about the man.  Check out:!/2009/11/albert-jones-interbiew.html

Kevin Paxson - PKV

BRJ's picture
The Greatest Visual Observer

Well...since the question does not stipulate amateur, or professional, but is suggestive of individuals more like ourselves, I would have say that in any such listing one name will always stand out above all others. That person was J. F. Julius Schmidt, without question the greatest visual observer of all time.

Schimdt (1825-1884) cannot easy be said to have had just one observing specialty...he observed ABSOLUTELY EVERYTHING! His greatest accomplishment was his enormous 25 section hand drawn lunar atlas (1878) which included 32,856 lunar craters and continued to be used by many amateurs well past the mid 20th century. In addition, he made 3,000 measurements of the heights of lunar mountains, discovered an endless number of lunar rilles and other detail, made a particular study of the crater Linne (200 observations), along with recording 38 lunar eclipses  including detailed color descriptions and hundreds of crated timings. Further, he made a detailed study of the visibility, color and brightness of the earthshine in young lunar crescents as seen from Athens Observatory. At the same time Schmidt was an equally prolific observer of the Sun, planets and comets, some of his drawings of the latter being among the most spectacular and detailed ever published. The man's drive was beyond imagination!

Schmidt created a  numerical color scale for describing the hues of various stars that saw significant popularity during the latter half of the 19th century. He likewise was an entusiastic observer of double stars. Between 1864 and 1879 he made detailed drawings of the nakedeye milky way. Two extraordinary, perhaps unrivaled, drawings derived from his data being published in 1923 long after his death.

From our standpoint as variable star observers his contribution to that field, as limited as it was in those days, would have ranked him today as among the AAVSO's greats. In his lifetime he amassed 85,000 estimates of the few variables known at the time, including nearly 10,000 estimates of delta Cep and 6,000 of beta Lyr!

Like most of us who are amateurs, Schmidt's approach to astronomy was almost strictly as an observer. His published papers rarely offered any sort of deep scientific analysis of his data from which could be drawn groundbreaking conclusions. He was basically a dynamic data generator and in that area unchallenged as the greatest visual observer of all time.

J.Bortle   (BRJ)

Glen chapman
For me William Herschell 

For me William Herschell 

pox's picture
I second that wholeheartedly.

I second that wholeheartedly. He pushed the boundaries of astronomy, all visual of course.

capricornus's picture
I'm curious about what types

I'm curious about what types of objects Jones, Peltier, Alcock, etc. were observing while accumulating their impressive numbers of observations. Did they seem to focus on specific categories (LPVs, cataclysmics, etc) or were they observing all types of variables?

PYG's picture
Re: I'm curious...

Alcock wasn't a VS observer as such.  He was a Nova & Comet hunter and Meteor observer.  He didn't knock out "impressive numbers" of variables at all.  He had a photographic memory of the night sky to at least magnitude 8, and could detect incredibly faint stars with the unaided eye - and all this whilst living in the close proximity of a brick factory in the cloudy skies of Peterborough in the Eastern part of England.  I think this is what makes him 'great'.  He didn't have the pristine skies of other great names mentioned here.  Just the cloudy, damp pretty miserable conditions of his home location.  And he never used a telescope of course.  He could also be inspiring just by being in the same room as you.  He's certainly a legend here in the UK.

BRJ's picture
The Greatest Visual Observers


I'm curious about what types of objects Jones, Peltier, Alcock, etc. were observing while accumulating their impressive numbers of observations. Did they seem to focus on specific categories (LPVs, cataclysmics, etc) or were they observing all types of variables?


Well, regarding Leslie Peltier's observing career it must be said that in his early days with the association our program was far less diverse than it is today. The more prolific observers simply observed whatever stars had charts available and the great bulk of these were LPVs. At the same time Leslie initially had only his 2-inch Strawberry Spyglass, supplanted shortly by a 4-inch refractor from the association's Telescope Loan Department and not long thereafter it was superseded by the RFT 6-inch comet seeker from Princeton. All of these instruments were better suited to what we today regard as relatively bright variables like LPVs and such was Leslie's regular observing program. Appreciate as well that the large telescopes more-or-less required to really follow most fainter CVs were a very rare commodity among amateur astronomers until following WWII.

With the advent of the 12-inch Clark from Miami University the situation changed. In the early 1960's the new and much larger scope allowed Leslie to see far fainter than his smaller instruments had formerly allowed and inspired him to take on programs that pushed even this mighty instrument to its limits. Among these I recall his monitoring of U Gem eclipses while the star was at minimum. The advent of the published "Inner Sanctum" listings in the 1960's likewise spurred the efforts of many to observe fainter and fainter stars. 

As an aspect of my editorship of the AAVSO Circular over the years Leslie would send me his monthly reports and these tended to illustrate his interest in now following the growing lists of CV stars.

It is perhaps interesting to note that many of our more prolific variable star observers down through the years have had their observing programs evolve in virtually this same manner as did Leslie's. Often they started out with bright LPVs and irregulars, those visible in binoculars and small aperture telescopes. This shifted to include the brighter CVs plus faint Miras when they obtained a moderate-sized telescope. Finally, upon eventually acquiring instruments perhaps in the 16 to 20-inch class they become mainly interested in old novae, the many very faint dwarf novae, extreme odd-ball CVs and such, almost to the exclusion of LPVs and other brighter stars.

J.Bortle   (BRJ) 

AAX's picture
Hi friends, Ok, let me talk

Hi friends,

Ok, let me talk about Jose Brazilicio de Souza (1856-1910). Maybe he wasn't "the-greatest-visual-observer-of-all-time", even something like "o-maior-observador-visual-brasileiro-de-todos-os-tempos". But what he did is amazing. Let's see:

He was professional musician: private piano lessons and public theater show.

He was professor on local city: Cosmography, Geography and History

He observed a lot of astronomical objetcs: double stars, comets, lunar eclipses, 1882 Venus transit, several moon craters and weather observations.

He published several articles in local newspapers regarding astronomical phenomena between 1882 and 1909.

More information (in Portuguese):

I would like to tell many things regarding another Brazilian great visual observers: Rubens de Azevedo, Jean Nicolini or Vicente Ferreira, but what we know is that someone "was-a-great-observer" and few data is available to check it.

PKV's picture

I only wish to note Argelander's contributions, not only his variable star observations, but for his Bonner Durchmusterung (BD) catalogue, which documented the positions and magnitudes of 324,198 stars down to -2 degrees South declination.  This represents a huge amount of transit work and note taking.   This catalogue, published in 1863, was the standard star catalogue until the very end of the 1800's and beyond, prior to photographic based catalogues.  Schonfeld and Kruger also assisted Argelander on the BD Survey.  Additionally, Argelander is the grandfather of variable star astronomy and his "step method" is still used by many today.  Kevin Paxson - PKV

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