Wednesday, March 8, 2017


Constellations That Might Have Been
By: Bob King | March 8, 2017

Obsolete constellations may be gone, but they're not forgotten. We revisit their brief glories and learn how to find them in the 21st-century sky.

Owl of Atlases Past

Noctua, the Owl, now defunct, evolved from an earlier obsolete avian constellation. Created by 19th-century English amateur astronomer William Jamieson, Noctua perched at the end of Hydra's tail between Libra and Spica (top) in Virgo.
Sidney Hall / Urania's Mirror
I suppose all constellations will be obsolete someday, replaced by revisionists of the distant future or simply so distorted by the motions of their individual stars that retooling will be essential. For now, we've got 88, and that's the way it'll be for a long, long time.

Those 88 survived a lengthy winnowing process that ended in 1930 when their borders were set for good by the International Astronomical Union.

The carcasses of constellations that might have been were discarded along the way, but not before these "might have beens" had their day, starring in a handful of old-time sky atlases during the acme of celestial cartography in the 17th and 18th centuries.

Seeing and finding patterns is one of humanity's greatest traits, so it was only natural to look for new ways to connect stars in parts of the sky that were still wild territory between existing groups. Because now-obsolete constellations occupied relatively blank spots in the sky, they were comprised of mostly fainter stars, as the bright ones had already been used for the more familiar constellations.

Obsolete Tri Minus, Hevelius

In his atlas Firmentum Sobiescianum (1690), Polish astronomer Johannes Hevelius introduced two small, obscure constellations that later fell by the wayside: Musca Borealis, the Northern Fly; and Triangulum Minus, the Small Triangle. Use the map below to find them on March evenings.
Johannes Hevelius
Paired Triangles

You can still find Hevelius's two additions to the fall–winter sky — Musca, the Northern Fly, and Triangulum Minus, the Small Triangle, near the non-defunct Triangulum. Both groups are composed of mostly 5th-magnitude stars, though Musca's brightest, present-day 41 Ari, shines at magnitude +3.6.
Created with Stellarium

Astronomers continued to use ancient myths as the basis for the new star patterns but also added additional, more modern, references, many of which related to then-current technology, such as: Machina Electrica, the Electrical Machine; Globus Aerostaticus, the Hot-Air Balloon; and Officina Typographica, the Printing Shop. Given a free hand in today's world, I'm certain Computatrum Novum and Telephonium Portabile would be part of our celestial scenery.

Monster Faces the Music
George's Harp, another constellation no longer in use, was created by Maximilian Hell, director of the Vienna Observatory in the mid-1700s. Originally called Psalterium Georgium, it was intended to honor George III of Great Britain who was the patron of William Herschel. A psaltery is a type of harp. The name was later changed by Johann Bode to Harpa Georgium in his 1801 celestial atlas Uranographia. 
Sidney Hall / Urania's Mirror
Mixing Music and Politics

You can find George's Harp, a scanty figure of 4th- and 5th-magnitude stars, tucked between Cetus and Eridanus. The other forgotten constellation in the vicinity is the Branderburg Scepter, introduced in 1688 by German astronomer Gottfried Kirch and named for the Brandenburg province of Prussia ruled by Frederick III. It's another another example of politics at play in the heavens.
Created with Stellarium

Others, like Edmond Halley of comet fame, used the opportunity for political favor and advantage. Perhaps this was his motivation  for creating the short-lived Robur Carolinum (Charles's Oak) in 1769, naming the figure for the British King, Charles II. Few heard the thud when it was chopped down 75 years later by French star mapper Nicolas Louis de Lacaille.

Stellar Atlas Giants

Left: Johannes Hevelius (1611–1687), Polish astronomer and celestial cartographer; Right: Johann Bode (1747-1826), German astronomer and atlas maker.
German astronomer Julius Schiller attempted to rid the night sky of pagan influences when he created the atlas Coelum Stellatum Christianum with figures based entirely on the Bible. Ursa Major became St. Peter's Boat and Corona Borealis, the Crown of Thorns. 

At least two dozen defunct groups including Bufo, the Toad, and Felis, the Cat, prowl the pages of books and atlases drawn up by famous celestial mapmakers like Johannes Hevelius and Johann Bode. But they didn't make the ultimate cut due to their obscurity, lack of good public relations, or inappropriate politics.

A Place A Bear Could Cool Its Paws

Jordanus, representing the Jordan River, was created by Dutch astronomer and cartographer Petrus Plancius for his celestial globe of 1612. Later, this lovely and lengthy constellation was broken into Canes Venatici, Leo Minor, and Lynx by Hevelius.

ECHO — Berlin
Forgotten Northern River

Jordanus Fluvius, or the River Jordan, once flowed beneath Ursa Major. It's now three separate constellations: Canes Venatici; Leo Minor; and Lynx.
Created with Stellarium

Most of us have a faint familiarity with two former constellations: Argo Navis, the Ship Argo, and Quadrans Muralis, the Mural Quadrant, where the radiant of the annual Quadrantid meteor shower is located. Argo was so large and unwieldy it was split into the three current constellations: Carina, the Keel; Vela, the Sails; and Puppis, the Poop Deck (or Stern).

Tough Guy's Final Labor

During the most dangerous of the twelve labors assigned by King Eurystheus, Hercules grasps Cerberus, a three-headed monster who guarded the gates of Hades. Hevelius introduced the constellation in 1687. 
Sidney Hall / Urania's Mirror
A Nasty Handful

As with most of the now obsolete constellations, Cerberus was created using obscure 4th- and 5th-magnitude stars in the backwaters of the brighter constellations. Hevelius introduced it in 1687. While seven of his figures have stood the test of time, this one bit the dust.
Created with Stellarium

I've always pined for some of the others, if only because they represent a few of my favorite animals — Noctua, the Owl being one. I thought it would be fun to resurrect them from obscurity like the dinosaurs of Jurassic Park. By tracking them down in the present day (night!), we can pay homage to an obscure bit of astronomical history, as well as honor the memory of astronomers who tried but failed to convince the world it needed a rooster, reindeer, and royal oak in the night sky.

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