Constellations: Grus 'the Crane'
Created | Updated Apr 27, 2016
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Puppis | Pyxis | Reticulum | Sagitta | Sagittarius | Scorpius | Sculptor | Scutum | Serpens | Sextans | Taurus
Telescopium | Triangulum | Triangulum Australe | Tucana | Ursa Major | Ursa Minor | Vela | Virgo | Volans | Vulpecula
To the whooping crane:
Let wings take you
South against all winds
And back again
Over Earth's prescribed arcs
That yield to this flighted healing
To reclaim your own place in the sky.
– Marilyn Peretti
The Constellation Grus
|Name:||Grus (Latin: 'crane')|
|Area:||365 sq deg|
|Co-ordinates1:||Right Ascension 22h, Declination −45°|
Grus2 is a modern constellation south of the celestial equator. It is a faint cross of stars, which, when joined in a certain way, resembles a large bird with long neck and stick-like legs. Grus 'the crane' made its debut in the 1603 Uranometria (star catalogue) of Johann Bayer. Historically it has also represented the stork (Anastomus), the heron (den Reygher) and the flamingo (as Phoenicopterus).
The crane is one of a dozen constellations delineated by Dutch astronomers Pieter Dirkszoon Keyser and Frederick de Houtman during their voyage to the southern seas between 1595 and 1597 on board the Hollandia. They drew up five3 star patterns to represent birds: Grus; Apus (bird of paradise); Pavo (the peacock); Phoenix (the mythological firebird) and Tucana (the toucan).
Bordered by Sculptor, Piscis Austrinus, Microscopium, Indus, Tucana and Phoenix, Grus has no Messier objects. However, there is plenty to satisfy the deep-space enthusiast, for it boasts an orchestra of galaxies, some of which are performing their own cosmic version of a Viennese waltz (see 'Grus Quartet' below).
The scientific star names are simple to understand (if you know your Greek alphabet). For example: the 'alpha' star means that it is the brightest star in that constellation. The next brightest is designated 'beta', etc. Combined with the genitive name, this is known as the 'Bayer designation'. Some stars have proper names as well; for example, alpha Gruis is Alnair. Other stars are known by their catalogue number.
The Stars of Grus
In antiquity the stars of Grus used to belong to Piscis Austrinus, so the name that alpha Gruis was saddled with was Alnair, literal meaning: 'the bright one in the fishtail'. Alnair is a blue-white giant which shines brighter than the supergiant beta by virtue of being 70 light years4 closer to us.
Beta Gruis is an irregular supergiant class M (red) which forms the point where the imaginary lines cross, creating the central heart of the bird, so an appropriate name of Cor Gruis could be assigned to it. A companion has been detected at 11AU (astronomical units) distance, but lack of information means it has never been classified.
Delta Gruis is a line-of-sight double with one yellow giant star (delta1) plus a red giant companion (delta2). Delta1 and delta2 each have a companion (from our vantage point) although neither are binary systems.
Mu Gruis is a binary system consisting two yellow dwarf stars.
Tau1 Gruis (HD 216435) is a yellow main sequence (dwarf) so it is similar to our Sun. In 2002 an extrasolar planet was discovered in orbit around it (see 'Extrasolar Planets' section below).
|α Gru||alpha Gruis||Alnair||+1.7||100||Blue-white giant|
|β Gru||beta Gruis||HD 214952||+2.1 var||170||Red supergiant|
|γ Gru||gamma Gruis||HD 207971||+3.0||200||Blue giant|
|ε Gru||epsilon Gruis||HD 215789||+3.5||130||White dwarf|
|δ Gru||delta Gruis||HD 213009/HD 213080||+4 var||av 300||Two double
|ζ Gru||zeta Gruis||HD 217364||+4.1||112||Yellow dwarf|
|ι Gru||iota Gruis||HD 218670||+3.9||180||Orange dwarf|
|θ Gru||theta Gruis||HD 218227||+4.5||130||Double|
|μ Gru||mu Gruis||HD 211088/HD 211202||+5 av||240-260||Binary|
|τ1 Gru||tau1 Gruis||HD 216435||+6 var||109||Yellow dwarf|
New General Catalogue (NGC) and Index Catalogue (IC)
The New General Catalogue was compiled by John Louis Emil Dreyer (the director of the Armagh Observatory from 1882 to 1916). This was later expanded to include newer discoveries, and is being continually updated as the NGC/IC Project.
IC 5148 is a spherical planetary nebula located 3,000 light years distant. It has the unofficial nickname 'the Spare Tyre Nebula'. NGC 7424 is a barred spiral galaxy some 40 million light years distant. It is thought to be of similar size and composition as our own Milky Way. In 2001, an exploding star, SN 2001ig, was recorded there. This rare Type IIb supernova was studied over the next two years by astronomers at the Australian Telescope Compact Array to try and determine why it changed from hydrogen-rich to hydrogen-poor.
Just below the border with Piscis Austrinus is the Grus Group of galaxies which includes: NGC 7410, NGC 7412, NGC 7418, NGC 7421, NGC 7424, NGC 7456, NGC 7496, NGC 7531, IC 1459, IC 5267, IC 5269 and IC 5273.
A Scot Down Under
Also part of the Grus Group is the Grus Quartet, a close ensemble of four large spiral galaxies discovered in 1827 by Scottish astronomer James Dunlop (1793 - 1848) while he was working at Parramatta Observatory, New South Wales, Australia. NGC 7552 and NGC 7582 have high starburst activity. NGC 7599 and NGC 7590 are clearly interacting in two places. Eventually they will form one amalgamated galaxy but this cosmic dance will take millions of years to complete.
Grus Quartet Table
|NGC||Dunlop||Galaxy Type||Brightness (m)|
|NGC 7552||Dun 475||Spiral||+10.7|
|NGC 7582||Dun 476||Spiral||+10.6|
|NGC 7590||Dun 477||Spiral||+12|
|NGC 7599||Dun 477-2||Spiral||+11.4|
Extrasolar Planets in Grus
There have been several extrasolar planetary systems found in the constellation Grus; the first was discovered in 2001. Figures given in the table below are the length of the planet's orbital period around its parent star, which we know of as a year. The mass of the extrasolar planet is compared to that of Jupiter, our Solar System's largest planet, known by astronomers as the 'Jovian scale'.
The star tau1 Gruis (catalogue number HD 216435) is 109 light years distant and has a confirmed gas giant planet, HD 216435 b. Tau1 Gruis is ringed on this map along with all the planet data.
Extrasolar Planets Table
|Star name or
|Year of discovery||Comments|
|Tau1 Gruis||HD 216435 b||1.5||1,443||2002||Gas giant|
|HD 213240||HD 213240 b||4.5||951||2001||Superjovian|
|HD 208487||HD 208487 b||0.7||123||2004||Gas giant|
|Gliese 832||Gliese 832 b||0.69||3,416||2008||Gas giant|
|Gliese 832||Gliese 832 c||0.015||35.6||2014||Super-Earth|
|HD 215497||HD 215497 b||0.017||3.93||2009||Super Earth|
|HD 215497||HD 215497 c||0.33||567||2009||Gas giant|
|WASP-95||WASP-95 b||1.13||2.18||2013||Hot gas giant|
The Crane, Stork and Flamingo in Modern Culture
Although this Entry is primarily about Grus the constellation, the author thought you might like to have some more earthly information about the large wading bird whom the star mappers Keyser and de Houtman honoured.
The crane (Grus grus) has a full moon named after it – the one in July, that is.
In Kung Fu martial art, Hoo Her Suan Sin is the Tiger-Crane combined movement; the power and strength of the tiger is teamed with the light control and fleetness of the crane.
In Feng Shui the crane represents an eternal quality that is essential for longevity, which could mean long life or length of time residing in a place, or a long marriage, etc. Also, followers of this ancient art believe that cranes (along with peacocks, pheasants and love birds) can help find happiness in the romantic area of a person's life.
The stork is the bird that traditionally delivers a new baby, safely contained within a blanket held in its long beak, to the family home. In some cultures the stork represents paternal care, because stork pairs will not abandon a nest even at their own peril.
Some people believe that if a stork builds a nest on your roof, then someone in the home will die before long. However, in some countries, eg Germany, having storks on your roof is considered lucky!
The stork who delivered Dumbo to Mrs Jumbo in Walt Disney's classic Dumbo was voiced by Sterling Holloway.
The flamingo has pink plumage thanks to their beta-carotene rich diet of blue-green algae, crustaceans and molluscs. Alice used a pink flamingo as a croquet mallet in the novel Alice's Adventures in Wonderland by Lewis Carroll.
'Pretty Flamingo' was a UK number one in 1966 for Manfred Mann.