Dorado

Lore & Background

Dorado was one of twelve constellations named by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. It first appeared on a 35-centimeter-diameter celestial globe published in 1597 or 1598 in Amsterdam by Plancius with Jodocus Hondius. Its first depiction in a celestial atlas was in Johann Bayer's Uranometria of 1603. In Johannes Kepler's edition of Tycho Brahe's star list in the Rudolphine Tables of 1627, it was given the alternative name Xiphias (the swordfish), but the name Dorado ultimately became dominant and was adopted by the IAU. Dorado represents a dolphinfish; it has also been called the goldfish because dorado are gold-colored.

Although the name Dorado is not Latin but Spanish, astronomers give it the Latin genitive form Doradus when naming its stars; it is treated as a feminine proper name of Greek origin ending in -ō (like Io or Callisto or Argo), which have a genitive ending -ūs. The South Ecliptic pole lies within this constellation, near the fish's head, and was called 'Polus Doradinalis' by Philipp von Zesen (aka Caesius). In Chinese astronomy, the stars of Dorado are in two of Xu Guangqi's Southern Asterisms: the White Patches Attached and the Goldfish.

Reader's Guide

Dorado's significance stems largely from its inclusion of most of the Large Magellanic Cloud, a satellite galaxy of the Milky Way located 179,000 light-years away and spanning 25,000 light-years. This galaxy contains over 10,000 million stars and has been deformed by gravitational interactions with the Milky Way. In 1987, it hosted Supernova 1987A, the closest supernova since the invention of the telescope. The constellation also contains the Tarantula Nebula (30 Doradus), larger and brighter than any nebula in the Milky Way at 1,000 light-years in diameter, illuminated by supergiant stars in the open cluster NGC 2070. Dorado features numerous deep-sky objects, including emission nebulae (N 180B, NGC 2014, NGC 2080), globular clusters (NGC 1755, NGC 1850, NGC 1854, NGC 2164), open clusters (NGC 1761, NGC 1820, NGC 1869, NGC 1901, NGC 1910, NGC 1978, NGC 2002, NGC 2027), and the superbubble N44. Notable stars include R Doradus, which has the largest-known apparent size of any star other than the Sun; WOH G64, a binary system containing the largest known star with a well-defined radius; and the hypervelocity star HE 0437-5439 escaping the Milky Way/Magellanic Cloud system. In early 2020, the exoplanet TOI-700 d was discovered orbiting the star TOI-700 in Dorado, the first potentially Earth-like exoplanet found by the Transiting Exoplanet Survey Satellite. Two United States Navy submarines, Dorado (SS-248) and Dorado (SS-526), were named after the same sea creature as the constellation.

Did You Know?

• The South Ecliptic pole lies within Dorado, near the fish's head.
• Supernova 1987A, the closest supernova since the telescope's invention, occurred in Dorado.