GENERAL ASTRONOMY ARTICLES

GREEK   LETTER   DESIGNATIONS
of  SOUTHERN   STARS

By Andrew James

“The origin of the constellations surrounding the South Pole is
involved in much obscurity. They have all been attributed to
various Dutch, Spanish, Portuguese, and Italian navigators,
but the original records of the observation and formation of
the different constellations appear to be lost.”

E. B. Knobel (1917)

Source : “On Frederick de Houtman’s Catalogue of Southern Stars, and
the Origin of the Southern constellations.”, MNRAS., 78, 5, (1917)

The ORIGIN of STAR DESIGNATIONS

“For himself [Zeus] it was who set the signs in heaven,
and marked out the constellations.…”

Aratos Phaenomena 270 B.C.

All initial designations for the stars and constellations date back into the long lost annals time. When conceived by humankind, these imagined stellar groupings were from the random patterns of stars in the Heavens, to represent themselves or others, the creatures they faced, or of stories reflecting on their day to day lives. They saw in the sky their hunting experiences needed for their daily sustenance; the man with his bow or spear, the creatures that they ate; sheep, bovine or fishes, or ones to avoid, like lions, bears or serpents. When night had fallen, they spoke of their daytime adventures, and so the patterns of stars became their storyboard canvas, to become their personal mythology. Ultimately this general representation became the worshipped gods that carefully echoed or revered the expected spiritual world beyond the grave.

At first, these general constellations names passed through the many generations. Through storytelling, they foretold and wisely embellished them for prosperity. From here soon came the common names of the brightest stars, whose related importance were of the constellations in which they appeared. Others too were given names based on apparent positions — as say, a foot or shoulder of the anatomical feature of some constellation figure they saw. Here several individual stars came as additional supplements to their increasingly convoluted stories. Thenceforth, like that of the early Ancient Greeks or Persians, that we derive most of the familiar constellations we recognised today.

ASSIGNING GREEK LETTERS to STARS

It was during ancient times when Nicaean-born Greek astronomer, Hipparchus (fl. c.146BC–c.127BC), now popularly known the Father of Astronomy, first introduced the idea of assigning Greek letters in order of the brightest to faintest naked-eye stars in each of the classical forty-eight constellations. Later this methodology was also adopted by Claudius Ptolemy (fl. 2nd AD.) Often some writers often wrongly attribute this to German Protestant lawyer Johann Bayer (or Philolaus) (1572-1625). Such a logical system again appeared within the 1603 original star atlas known under the shortened title just as Uranometria — from the more lengthier name “Uranometria : Omnium Asterismorum Continens Schemata, No a Methodo Delineata, Aereis Laminis Expressa.” It was first published by Christophorus in Augsburg, Germany, under the Latinised name Bayer or Ioannis Bayeri Rhainani I.C..

Such a similar designation system continues today.

Uranometria is probably more famous, as it was the first detailed star atlas that useful identified all naked-eye stars and the basic constellation outlines. Like most books of its day, the original printed images were fully engraved, which was drawn by Alexander Mair. This elegant atlas has several editions, including a total of fifty-one detailed maps. Opposing each map is a page listing all the bright stars. Here appears the Latin and Greek named stars, and if available, the main Bayer’s designation, stellar magnitude, and what part its star represents within the constellation — the latter being very similar to Ptolomy’s earlier star catalogue. All southern stars appear on Map 49 at the book’s rear, with an additional twelve new southern constellations. (See Figure 1)

Fig. 1. SOUTHERN CONSTELLATIONS in BAYER’s 1661 URANOMETRIA

This figure is by Bayer showing the main far southern constellations as of 1661, though Bayer had first employed these in 1603. These far southern constellations were likely originally taken earlier from Petrus Plancius. Most of these are odd collections, representing birds and aquatic reptiles or fish.
Starting on the left hand side from the fabulous Phoenix, finds the constellations above Grus (The Crane), the Indus (The Indian) and then Pavo (The Peacock). Below Phoenix and Grus, and halfway to the South Celestial Pole is Tucana (The Toucan) and below it Hydrus (The Water Snake). On the opposing page is Apus, drawn here as the Bird of Paradise, though it is now recognised as a bee. [Not listed as a Bayer constellation, is Triangulum Australe, which prior to this was considered a part of Norma as geometric drawing tools of the triangle, square and rule, plus later, the Circinus the Compasses. Norma here extended up to the eastward region from Antares.] Below Apus is Chameleon, and below it, Volans (the Flying Fish), and at the middle bottom, Dorado (The Goldfish), which is sometime referred as Xiphias (Swordfish) I.e. Uranometria by Johann Elert Bode in 1801. Above it is the Large Magellanic Cloud (LMC), and the Small Magellanic Cloud (SMC) under Hydrus, which is arguably given as separate constellations. Note also the bright stars of Achernar, Miaplacidus and Alpha Centauri are drawn, though the bright star Acrux and other Crux stars are obviously missing. Also the band of the Milky Way shows not resemblence how it really appears. Significantly he also does not show the Coal Sack at all.
This figure also shows the circle of the south polar cap extending out by 23½° (Declination −66½°), with the second circle being the the south elliptal pole. Four meridan lines show the directions of 0h, 6h, 12h and 18 hours and its equivalent in ecliptical longitude. (A more general discussion on the southern constellations see Part 1 : The Origin of the Constellations)

This is followed by Maps 50 and 51, which show the whole northern and southern hemisphere caps. Most famous for all Antipodean observers is probably the stylistic engraved image of the entire constellation of Argo Navis — the fabled ancient story of the Greek ship of Jason and the Argonauts. His same drawn ship is aptly given by the Greek Aratos of Soli (fl. c.315 BC – c.245 BC), who says in the renown historical poem Phaenomena dating back to 270 B.C.;

“Beside the tail of the Great Dog the ship Argo is hauled stern-foremost. For not hers is the proper course of a ship in motion, but she is borne backwards, reversed even as real ships, when alread the sailors turn the stern to the land as the enter the haven, and every one back-paddles the ship, but she rushing sternward lays hold of the shore. Even so is the Argo of Jason borne along stern-foremost. Partly in mist is she borne along, and starless from her prow even to her mast, but the hull is wholly wreathed in light. Loosed is her Rudder and is set beneath the hind feet of the Dog, as he runs in front.”

Fig. 2. ARGO NAVIS in BAYER’s URANOMETRIA

This is an example of Bayer’s southern map of the mega-constellation of Argo Navis. Note that the northern part of the map, including all the 1st and 2nd magnitude stars have Greek letters assigned, but those further south are simply designated ‘d’, etc. Looking at the False Cross, the stars are clear distorted when compared to how they appear in the sky today. Canopus / α Argus (now α Carina) has been placed at the stern on the waterline that guides the rudder of the fabled ship. A rock piecing out of the water conveniently hide the bow from view, which I assume might be the island occupied by the Sirens that lies according to Homer between Aeaea and the rock of Scylla in Aegean Sea. On the other side of the rock (left) is Centaurus and the Cross, marking a quite different “chapter” of the Greek stories from the Ancient world.

A few of Bayer’s original charts still exist. Most of the information about these charts are taken from the revised edition of Uranometria published later in 1732 — a copy of which exists in the Royal Astronomical Society (R.A.S.) Library in London. These latter charts are reproductions of the originals, with little modifications or changes, and I did once inspect a set of these in England in October 1996 at an exhibition at the British Library. Both appeared more like works of art than historical astronomical documents.

Yet there are some questions about the origin of Bayer’s designations. For example, according to the author and astronomical popularist Richard Allen, in his book “Star Names: Their Lore and Meaning.” (1899), has first challenged this by saying Piccolomini of Siena adopted this same procedure some fifty years earlier. In fact, this just highlights the perpetuated misconception still frequents many familiar astronomical books.

So, although Bayer or Piccolomini did apply these letters to those to those constellations north of about −50° declination, they never assigned them Greek letters to the ‘newer’ ones in the far south. Bayer, when he did, had really adopted only the designs from several engravings made by Albrecht Dürer (1471-1528) in 1515.

Modern writers often place Bayer on a high pedestal, venerating him as some significant influential force in the development of astronomy. Unfortunately, his eventual known reputation is a little shadier. Again, Richard Allen says of Bayer that he was; “…a poor and inexact cartographer”; and that; “…a work much tinctured with the occult science.”

We are often told that the modern constellations were passed down from ancient times, however, no direct evidence of their entire shapes or component stars truly exists today. Bayer’s important contribution was simply to attempt to reapply ancient lore with the visible night sky. In regards the shaping of the constellations and the designing the newer southern ones, Bayer never created nor observed them — all he did was exclusively apply his imagination to the assumed names. The southern skies were different, as his knowledge was either entirely second or third hand.

Conversely, Bayer had no problems with the northern stars. All he had to do was literally walk out the backdoor and look up. Southern positional observations and descriptions used in the original Uranometria were exclusively made by the Dutch southern explorer Pieter Dirckz Keyser (Pieter Theodori) (?-1596). Another prominent misconception example of was Bayer’s alleged discovery of the brightest globular star cluster ω Centauri. However, the true designation of this ‘hazy star’ should be Keyser and not Bayer. Simply as Bayer never labelled the object as Omega!

GREEK LETTER DESIGNATIONS in CRUX

Although the figures are magnificent and are skilfully drawn, the stellar positions are far from perfect. An example is the area of Crux and Centaurus. In the 15th Century, Crux was a sub-constellation of Centaurus —existing only as a mere asterism. The image portrayed is of the centaur Chiron (or Chyron) viciously spearing Lupus the Wolf. At the rear of the hind legs is the crucifix image of the asterism known as ‘Thonis Caesaris’ (or Thronos Caesaris), named by the ancient historian Pliny the Elder (or Gaius Plinius Secundus Pliny) (23AD-79AD) in honour of the Roman emperor Augustus. [Book 2 : “Natural History”] Crux then was visible on the southern horizon from Rome during April and May, though due to the precession of the equinoxes it is not visible there today. Ptolemy could easily see both these southern constellations, so he just placed Crux into Centaurus. (These three images are from Bayer’s 1732 edition of Uranometria, and can searched for on the Net.)

Oddly, the early Christian church remarkably never adopted Crux as their representative symbol of the worldly death of Christ. From the 13th Century, seafaring explorers south the equator held some romanticism with Crux — deifying these stars by reinforcing their Christian faith against the fear of the unknown. Bayer formulated the labelling of the principle stars of Crux (as listed originally in Bayer’s own associated catalogue.)

Errors also appearing in the drawn caricatures are appallingly inaccurate. In all, these strategically placed stars do not to match the constellation outline, but to fulfil the caricature for example, α [alpha] Centauri is placed high above the Cross, while β [beta] Centauri is on the opposite side of the cross near the current position of δ [delta] Centauri. The star ε [epsilon], however, is not drawn in the chart. As for the other new constellations of the south, Bayer added no useful lettering system. It was Jakob Bartsch (Bartschius) who published these in the “Planispaerium Stellatum” — made in 1624 during the final year of Johann Bayer. However, all had exactly the same stars seen in Centaurus and Crux in the original Uranometria Bayer chart.

In 1679, Augustin Royer is said to have named Crux as a seperate constellation. Others have suggested it was Englishman Emeric Mollineux in 1592, though Allen says he suspects that it origin was two hundred years before this. Royer then re-labelled the first six stars in Crux from the old Centaurus letters from; α [alpha] through ζ [zeta].

GREEK LETTER and OTHER DESIGNATIONS
in SOUTHERN CONSTELLATIONS

Modern Greek designations for southern constellations were again applied during the years by the French “Southern Columbus” Nicolas Louis de Lacaillé (1713-1762) after he had done his main astrometry in South Africa. In 1752 and 1753 he used a new method by using the Greek letters, and when the ran out, he just added Roman letters. Here the many large Milky Way constellations of the southern hemisphere now start an additional method applying also upper and lower case Roman letters. I.e. A to Q & a to z, but not the letters R to Z — because they were to be reserved exclusively for variable stars. He firstly applied this to the mega-constellation of Argo Navis, labelling some 180 stars, and following this same system with the constellations like Centaurus and Lupus.

According to the American Benjamin Apthorp Gould (1824-1896), a grand 829 stars were visible to the naked-eye within Argo Navis, thus making up 11% of all viewable stars to the naked-eye. Lacaillé’s adopted system was to stay in limbo for many years. Only a few of this numbering system remains, like the second brightest globular in the sky known as 47 Tucanae (NGC 104), who Lacaillé’ catalogue lists as a ‘star’. This was again succeeded with the adoption of another naming system produced by the “British Association Catalogue” (B.A.C.) in 1845.

In 1729, John Flamsteed’s (1646-1719) usage first superseded the exclusive use of just Greek letters. He sensibly labelled all naked-eye stars that were visible from Greenwich, England by ordering them by an increasing number for each constellation. This appeared in his first star atlas, which was published after his death, along with another newer and slightly modified division of the brighter stars by Greek letters. As he could not see many southern constellations, this numbered system suddenly halts around declinations south of −30°.

No doubt, Centaurus is the classic example of the division between northern and southern hemisphere stars. In the north, the constellation is 1,2,3,4 and 5 Centauri while in nearby constellation of Lupus, has only 1 and 2 Lupi. Yet below declination −33°, Roman letters are then exclusively applied. I.e. x Centauri and y Centauri — each positioned at the lower declination of −34°.

Overall, the many inherent problems with this random naming process is that the astronomers could never get some internationally agreed system applying to the constellations universally accepted. This made any subsequent classifications or ideas appear very arbitrary. “Miss Clerke” in “The Herschels and Modern Astronomy” properly and aptly describes it as being ; “…a system of derangement and confusion.” They did not achieve ratification of the eighty-eight constellations until 1930, when the International Astronomical Union finally agreed on them. This convoluted mess in labelling of Greek letters (and Roman letters) for southern stars was added literally ad-hoc between 1680 and the late-1800s.

Only certain constellations have Greek lettered stars below 5th magnitude, while others even above 3rd are sometimes ignored. It is likely that they make the labelling systems simply to define the outline of the constellation and were never properly or logically organised based on stellar magnitudes. South of declination −55°, the number of Greek letters does not correlate with magnitude but the area of each individual constellation. For example, the similar sized northern constellation of Sagitta has the same problems as Greg suggests for Crux. Here its lowest Greek letter is Zeta (ζ), although Epsilon (ε) is at the lowly magnitude of 5.6v — and 10 and 13 Sagittae are both brighter! If some global application of standardised letters were placed on Sagitta, ‘Omega’ Sagitta would be below naked-eye visibility!

Central to the real problem here is it is systemic of the days when romantic astronomy bore some general interest to the public. Greg’s own use of the latest Hipparcos Catalogue data among the gist of the written text — just highlights the difference in our current perceptions of what astronomy is about. As a general criticism, we cannot really apply the notions of modern astronomy to the antiquated notions from the days of early observational astronomy. They are separate. (I too am equally guilty of this point, as this also appears in my other related article in UNIVERSE — See “Gacrux and the Naming of Southern Stars”)

In my own opinion, as a visual observer and part-time astrognosist (meaning essentially non-telescopic observer), these ‘niceties’ are important — though they do not pertain at all to the modern astrophysical views of our current technologically savvy astronomy.

Changes to constellation names and designations are not new. Sir John Herschel and Francis Baily in 1841 suggested a reformation in the naming and assignment of Greek letters to the Royal Astronomical Society. It did not work. As Richard Allen rightly says; “.…their changes were too sweeping and were not successful…”

Today creating such ‘neo-formal Greek designations’ would likely more trouble than it is worth. The I.A.U. has open views on this subject, and amateurs could collectively approach the I.A.U. Commission 5 ‘Task Group on Astronomical Designations’, though your chances of success are pretty slim at best. Commission meetings are mostly scheduled every three years, next likely being 2017.

The I.A.U. would likely disagree with us. This is stated in Fernandez, Lortet and Spite in “The First Dictionary of the Nomenclature of Celestial Objects”, A&A., 52, 4, June (1983) (Section 5; Heading Number 2), as; “Nomenclature based on constellation name: a (very) confusing practice.”

However, if there is some general agreement approaching the problem sensibly among most astronomers — amateur and professional alike, it might just be possible.

A MODERN NUMERICAL SOUTHERN STAR CATALOGUE?

My own radical approach might be to introduce some Southern Flamsteed Catalogue (SFC), made along the lines of Benjamin Gould’s Uranometria Argentina at Epoch 1875.0, but with a better and higher magnitude limit. Here among individual southern constellations, each star is numbered based in order of increasing Right Ascension, with limiting magnitude down to 5.8v — the same as the original visual magnitude limit given by Flamsteed and further south by Elert Bode. Numbers already used in constellations south of −30° declination, could then be reassigned a new SFC number, and introducing these systems would apply to about 1,800 stars. Largest number would be about 230 in the constellation of Centaurus. One minor problem is the 1725 epoch used by Flamsteed, which has meant that the proper motions have begun to mix up these numbers. For example, 20,21,22,23 Herculis has been now reordered in Right Ascension as 22,20,23,21 Herculis. Were such an index was applied to the southern stars, should it be the 1725 epoch or 2000 epoch?

Furthermore, overall consequences would definitely affect the modern celestial cartographers, as all atlases and most astronomical software would need updating. If we truly adopted such a system, Epoch 2050.0 star atlases could possibly adopt such changes. Do amateurs need such identification? I leave that to you.

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Last Update : 6th October 2017

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