Observation The Invention of Southern Skies

Until the time of the Great Discoveries in the 15th and 16th centuries A.D., the sky of the southern hemisphere has remain about unknown. Greek astronomers only working from Ptolemaic Egypt, or Arab astronomers and even Chinese or Indians travelling in distant lands could have a glimpse of these heavens and the objects it contained, besides which the representation of skies by the southern hemisphere cultures. Astronomers in the Mediterranean area also could have had a access to southern skies due to the precession of the equinoxes. Astronomical works of southern sky's inventors during Modern Era are most of the time part of the undertakings of that time to make maritime journeys safer and more accurate. Most quoted names in terms of those who contributed to the development of the southern skies are those following in that text. Not to be forgotten too that the captains of the Great Discoveries time were the first to report observations of southern skies, like Magellan or Amerigo Vespucci. Amerigo Vespucci, during one of his journeys around 1500, passed the equator, as he reported having 'a pole and the other at the end of our horizon,' and losing sight of Polaris, which was called the 'star tramontane' at the time. Astronomical knowledge then were however already sufficient so that they might determine a latitude through the altitude of the Sun and the analemna like it could be done in the northern hemisphere. Vespucci sought a equivalent of Polaris to the southern hemisphere ashe discovered, in the vicinity, the Southern Cross, a group of four stars forming like a almond, which reminded him of Dante's 'to better see the other pole, where four stars were shining, that only early humans could contemplate.'

Endeavors of Dutchmen (Late 16th Century)

After that, by the end of the 16th century A.D., those were the Dutch people who did advance the representation of the southern sky. Petrus Plancius (1552-1622), who had been born in West Flanders, a minister of the Dutch Reformed Church, moved to Amsterdam whence he had access to Portuguese nautical maps. He thus turned a expert of sea routes to India, being one of the founders of the Dutch Company of the East Indies and imposing the Mercator projection on navigational charts. Plancius knew very well explorer Henry Hudson. In 1589, with cartographer Jacob Floris van Langren, he manufactured a celestial globe of 12.8 inches in diameter which, for the first time, was describing the southern sky objects for which available information was extant, Crux, the Southern Cross, Triangulum Australe, the Southern Triangle and both Magellanic Clouds -which were then called 'Nubecula Major' and 'Nubecula Minor,' respectively. That was Plancius who asked Keyser to help filling in the sphere's blanks of the sphere, particularly around the southern celestial pole. Pieter Dirkszoon Keyser (1540-1596), a Dutch navigator, was formed mapping southern stars by Petrus Plancius. While he already knew Brazil, Keyser turned the second master and chief-navigator to the first Dutch expedition bound for the East Indies, the 'Eerste Schipvaart,' who left Holland by 1595. It looks like it was in Madagascar, a stop where the expedition refitted food and forces, that he performed most of his astronomical observations. Keyser died in the East Indies during the expedition. Was also part of the expedition Frederick de Houtman (1571-1627) and Vechter Willemsz, who were able to return to the Netherlands in 1597, bringing with them the new observations to Plancius. This was Plancius, who on the basis of the observations of Keyser and those of Houtman, planted the 12 new constellations on a new globe (13.8 inches), which he did with the artist, cartographer and engraver Jodocus Hondius the Elder (1563-1612; Hondius had already mapped the discoveries of English explorer Francis Drake) by 1597 or 1598. Total, Keyser, Houtman and Plancius were at the origin of 12 new constellations which names were derived from natural or mythical history, or explorations of these regions, like the chameleon, the peacock, the flying fish, the phoenix, the water serpent, etc.) Keyser's own observations were published in the appendix to his posthumous dictionnary and grammar of Malayan and Malagasy languages of 1603. Houtman, as far as he is concerned,returned to other expeditions as he had the opportunity to sail along the West coast of Australia or he was taken prisoner by the Sultan of Aceh, at the occasion of which he added yet other southern sky stars. It was Willem Janszoon Blaeu, who had already taken over the Plancius/Hondius globe in 1602, who created a new one in 1603 from the new observations of Houtman. Plancius, on a globe dated 1612 (or 1613), created 8 other new constellations, of which Camelopardalis, the Giraffe and Monoceros, the Unicorn only are still extant

From Bayer to Lacaille (17th and 18th Centuries)

Those first 12 new constellations were taken, finally, with credit to Keyser but without reference to Plancius, by Johann Bayer in his Uranometria, a celestial atlas of 1603, making that those twelve are sometimes falsely attributed to Bayer himself. Johann Bayer (1572-1625) was a magistrate in Augsburg, Germany who was passionate with astronomy. His celestial atlas was the first to encompass the celestial sphere entirely as it features one chart for each of Ptolemy's constellations, one for the skies located farther South and two planispheres. Bayer, beyond the Dutch observations, also worked upon Tycho Brahe's data. Edmund Hally (1656-1742) after that, a Englishman, a astronomer and a engineer, settled by 1676 on the St. Helena island, in the southern Atlantic Ocean in the purpose of drawing up the first chart ever of southern skies. That endeavor was supported by the Royal Society of London. That celestial chart was the first to be accurate. From that same period, Isaac Habrecht is also of note, a Swiss clockmaker who constructed the second astronominal clock of Strassburg, current France, about 1570, who is credited with having deviced the constellation of Rhombus (which turned into Reticulum, the Reticle). Or Jacob Bartsch (1600-1633), a German astronomer, husband to daughter to Kepler, who published several stars charts under the generic name of 'Usus astronomicus planisphaerii stellati' ('astronomical use of a starry planisphere') as they included the constellations deviced by Plancius in 1613 plus Crux and Reticulum. Johannes Hevelius (1611-1687) at last, a Pole, a brewer and a astronomer (as he is above all known for having founded lunar topography with his Selenographia in 1647. He classified and labelled more than 1,500 stars as his 'Firmamentum Sobiescianum' of 1690, a celestial atlas of 56 sheets, is containing 7 new constellations always in use nowadays, of which the Sextant for the southern hemisphere. Augustin Royer, as far as he is concerned, was a French astronomer under King Louis XIV as he published a catalogue of stars by 1679 in which he was taking again previous additions and several constellations of his own. Of which were retained only Columba, the Dove (which had been taken from Canis Major) and Crux, the Southern Cross he had officialized, which had been taken from Centaurus, the Centaur only. Let's come to a end with abbot Nicolas Louis of Lacaille (1713-1762), one of the main Franch astronomers in the 18th century, pupil to Cassini. He participated into the measurement of the French meridian line in the Pyrénées moutains. He also performed a long mission between October 1750 and June 1754 in the southern hemisphere to keep there with measurements of the arc of longitude and he took the occasion to build a astronomical observatory in Capetown, current South Africa, whence he performed a impressive number of observations. 14 constellations from 88 owe him their name as they were published in the 'Coelum australe stelliferum' in 1763. Lacaille took those in the range of science tools of that time, like the compass, the table, the ship's compass, the reflector, etc. We are indebted to Lacaille with the splitting of the very ancient and very large constellation of ship Argos into the Ship's Keel, Stern and Sails, as he did that for practical reasons