Grus is a constellation that can be found in the southern sky. Its name comes from the Latin word crane, which refers to a sort of bird. It is one of Petrus Plancius' twelve constellations, based on observations by Pieter Dirkszoon Keyser and Frederick de Houtman. Grus was initially drawn in Johann Bayer's star atlas Uranometria of 1603 and first appeared on a 35-centimetre-diameter (14-inch) celestial globe produced in Amsterdam in 1598 by Plancius and Jodocus Hondius. In 1756, a French adventurer and scientist Nicolas-Louis de Lacaille assigned Bayer labels to the constellation's stars, some of which had previously been assigned to the neighbouring constellation Piscis Austrinus. The "Southern Birds" are the constellations Grus, Pavo, Phoenix, and Tucana combined.
Alpha Gruis, the brightest star in the constellation, is also known as Alnair and is a 1.7-magnitude blue-white star. Beta Gruis is a red giant variable star with a brightness of 2.3 at its minimum and 2.0 at its highest. Planets have been discovered in six-star systems, including the red dwarf Gliese 832, which is one of the nearest stars to Earth with a planetary system. Another, WASP-95, has a two-day orbiting planet. The planetary nebula IC 5148, commonly known as the Spare Tyre Nebula, and the Grus Quartet, a group of four interacting galaxies, are among the deep-sky features located in Grus. |
History
Originally, the stars that makeup Grus were thought to be part of the nearby constellation Piscis Austrinus (the southern fish), with Gamma Gruis representing the fish's tail. The stars were first defined as a separate constellation by Dutch astronomer Petrus Plancius, who created twelve new constellations based on observations of the southern sky by Dutch explorers Pieter Dirkszoon Keyser and Frederick de Houtman, who had sailed to the East Indies on the Eerste Schipvaart, the first Dutch trading expedition. Grus was initially featured on a 35-centimetre-diameter celestial globe issued by Plancius with Jodocus Hondius in Amsterdam in 1598. It was initially depicted in a celestial atlas in Johann Bayer's Uranometria, published in 1603. The same year, De Houtman listed it in his southern star catalogue under the Dutch name Den Reygher, "The Heron," but Bayer used Grus, as did Plancius and Hondius. The name Phoenicopterus (Latin for "flamingo") was briefly used for the constellation in the early 17th century, as evidenced by Paul Merula of Leiden University's 1605 work Cosmographiae Generalis and a c. 1625 globe by Dutch globe maker Pieter van den Keere. The symbolism most likely came from Plancius, who had worked with both guys, according to astronomer Ian Ridpath. The "Southern Birds" include Grus and the adjacent constellations Phoenix, Tucana, and Pavo. (Moore 2000) From China, the stars that corresponded to Grus were often too far south to be visible. Gamma and Lambda Gruis, as well as stars from Piscis Austrinus, may have been included in the tub-shaped asterism Bàijiù in Chinese astronomy. The Arrernte and Luritja people residing on a mission at Hermannsburg in Central Australia saw the sky as divided between them, with Arrernte camps east of the Milky Way and Luritja camps west. The Arrernte claimed Alpha and Beta Gruis, as well as Fomalhaut, Alpha Pavonis, and the stars of Musca. (Johnson 1998) |
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Characteristics
Piscis Austrinus to the north, Sculptor to the northeast, Phoenix to the east, Tucana to the south, Indus to the southwest, and Microscopium to the west from the borders of Grus. In his Uranometria, Bayer bent Piscis Austrinus' tail to create room for Grus. It is the 45th largest of the eighty-eight contemporary constellations, covering 366 square degrees and 0.887 percent of the night sky. The International Astronomical Union selected the three-letter acronym "Gru" for the constellation in 1922. (Russell 1922) Belgian astronomer Eugène Delporte defined the official constellation borders in 1930 as a six-segment polygon. The right ascension coordinates of these borders are between 21h 27.4m and 23h 27.1m in the equatorial coordinate system, while the declination coordinates are between 36.31° and 56.39°. Grus is too far south to be seen by observers in the British Isles and the northern United States, while it may be seen readily from Florida or California (Moore 2001); observers south of latitude 33°N can see the entire constellation.
Piscis Austrinus to the north, Sculptor to the northeast, Phoenix to the east, Tucana to the south, Indus to the southwest, and Microscopium to the west from the borders of Grus. In his Uranometria, Bayer bent Piscis Austrinus' tail to create room for Grus. It is the 45th largest of the eighty-eight contemporary constellations, covering 366 square degrees and 0.887 percent of the night sky. The International Astronomical Union selected the three-letter acronym "Gru" for the constellation in 1922. (Russell 1922) Belgian astronomer Eugène Delporte defined the official constellation borders in 1930 as a six-segment polygon. The right ascension coordinates of these borders are between 21h 27.4m and 23h 27.1m in the equatorial coordinate system, while the declination coordinates are between 36.31° and 56.39°. Grus is too far south to be seen by observers in the British Isles and the northern United States, while it may be seen readily from Florida or California (Moore 2001); observers south of latitude 33°N can see the entire constellation.
Deep-sky Objects
IC 5148 – Spare-tyre Nebula – Planetary Nebula
NGC 7552 – Barred Spiral Galaxy
NGC 7590 – Spiral Galaxy
NGC 7599 – Barred Spiral Galaxy
NGC 7582 – Spiral Galaxy
IC 1459 – Elliptical Galaxy
NGC 7424 – Barred Spiral Galaxy
NGC 7213 – Lenticular Galaxy
NGC 7410 – Spiral Galaxy
Main stars - 8
Bayer stars - 28
Stars with planets - 6
Stars brighter than magnitude 3.00 - 3
Stars within 32 Ly - 1
Bordering
constellations
IC 5148 – Spare-tyre Nebula – Planetary Nebula
NGC 7552 – Barred Spiral Galaxy
NGC 7590 – Spiral Galaxy
NGC 7599 – Barred Spiral Galaxy
NGC 7582 – Spiral Galaxy
IC 1459 – Elliptical Galaxy
NGC 7424 – Barred Spiral Galaxy
NGC 7213 – Lenticular Galaxy
NGC 7410 – Spiral Galaxy
Main stars - 8
Bayer stars - 28
Stars with planets - 6
Stars brighter than magnitude 3.00 - 3
Stars within 32 Ly - 1
Bordering
constellations
- Piscis Austrinus
- Microscopium
- Indus
- Tucana
- Phoenix
- Sculptor