Pieter Dirkszoon Keyser

Pieter Dirkszoon Keyser also called Petrus Theodorus ( Emden , * 1540 ; † September 11, 1596 near Bantam ) was a Dutch navigator . Together with Frederick de Houtman he made star maps of the southern sky, where he introduced twelve new constellations.

Life

Little is known about early life. Keyser took part in some expeditions, including a. to Brazil and Novaya Zemlya .

In 1595 a fleet of four ships under the command of Cornelis de Houtman sailed via Madagascar to East Asia, the - disastrous - first Dutch East India expedition. Keyser was navigator on the Hollandia, later on the Mauritius.

Keyser had been commissioned by the cartographer Petrus Plancius to make observations of the deep southern sky. The Europeans did not yet have reliable data on the stars in these regions. From the masthead of the ships he observed the night sky with an instrument he had received from Plancius (possibly an astrolabe or Jacob's staff ). He was assisted by Frederick de Houtman, the commandant's younger brother.

Of the 249 participants, only 87 returned alive; the majority had died as a result of illness and violence. Keyser died in September 1596 when the fleet was off Bantam ( Java ). His star catalog was given to Plancius by de Houtman in 1597 after the return of the fleet.

Sky mapping

Bayer: Uranometria , reprint 1661, sheet 49 shows the southern sky

Keyser and de Houtman prepared a catalog with 135 stars and divided the southern sky into twelve new constellations :

Het Chameljoen ( chameleon )
The Dorado ( swordfish , literally "goldfish")
Den voghel fenicx ( phoenix )
De Indiaen ( Indus )
Den Indiaenschen Exster, op Indies Lang ghenaemt ("Indian Magpie", the toucan )
De Paradijs Voghel ( Bird of Paradise )
De Pauww ( peacock )
The Reygher ("heron", today crane )
De Waterslang ( Little Water Snake )

De Vlieghe ( fly )

De vlieghende Visch ( Flying Fish )

Den Zuyder Trianghel ( Southern Triangle )

Keyser's twelve new constellations appeared - some under a different name first - in 1597/1598 on a celestial globe by Plancius , two years later also published by Jodocus Hondius , and in 1602 by Willem Blaeu , in 1603 also with the observations of de Houtman's second voyage. Johann Bayer took it over in his 1603 sky atlas Uranometria . Today they belong to the 88 recognized constellations.

In addition, lists Keyser altar , Argo Navis , Centaur , Corona Australis , the Southern Cross , Wolf , Dove as De Duyve met the Olijftak ( "The dove holding an olive branch"), Eridanus as the Nyli ( "Nil") and the tail of the Scorpion .

Keyser's notes appeared in tabular form in Johannes Kepler's Tabulae Rudolfinae ( Rudolfinische Tafeln ) in 1627 . However, the original recordings have been lost.

Source

Willem Lodewycksz (1997). Om de Zuid: de eerste schipvaart naar Oost-Indië onder Cornelis de Houtman, 1595–1597. Vertaling, inleiding en annotaties Vibeke Roeper en Diederick Wildeman. SUN, Nijmegen.

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personal data
SURNAME	Keyser, Pieter Dirkszoon
ALTERNATIVE NAMES	Peter Theodorus
BRIEF DESCRIPTION	Dutch navigator
DATE OF BIRTH	1540
DATE OF DEATH	September 11, 1596
Place of death	at Bantam, today Semarang