Beta Gruis (β Gruis, abbreviated Beta Gru, β Gru), formally named Tiaki , is the second brightest star in the southern constellation of Grus. It was once considered the rear star in the tail of the constellation of the (Southern) Fish,

Piscis Austrinus Piscis Austrinus is a constellation in the southern celestial hemisphere. The name is Latin for "the southern fish", in contrast with the larger constellation Pisces, which represents a pair of fish. Before the 20th century, it was also known a ...

: it, with Alpha,

Delta Delta commonly refers to: * Delta (letter) (Δ or δ), a letter of the Greek alphabet * River delta, at a river mouth * D ( NATO phonetic alphabet: "Delta") * Delta Air Lines, US * Delta variant of SARS-CoV-2 that causes COVID-19 Delta may also ...

Theta Theta (, ; uppercase: Θ or ; lowercase: θ or ; grc, ''thē̂ta'' ; Modern: ''thī́ta'' ) is the eighth letter of the Greek alphabet, derived from the Phoenician letter Teth . In the system of Greek numerals, it has a value of 9. Gr ...

Iota Iota (; uppercase: Ι, lowercase: ι; ) is the ninth letter of the Greek alphabet. It was derived from the Phoenician letter Yodh. Letters that arose from this letter include the Latin I and J, the Cyrillic І (І, і), Yi (Ї, ї), and ...

, and

Lambda Gruis Lambda Gruis, Latinized from λ Gruis, is a solitary, orange-hued star in the southern constellation of Grus. With an apparent visual magnitude of 4.47, it is visible to the naked eye as a faint point of light. The distance to this sta ...

, belonged to Piscis Austrinus in medieval Arabic astronomy.

Nomenclature

''β Gruis'' ( Latinised to ''Beta Gruis'') is the star's Bayer designation. It bore the traditional Tuamotuan name of ''Tiaki''. In 2016, the IAU organized a

Working Group on Star Names The International Astronomical Union (IAU) established a Working Group on Star Names (WGSN) in May 2016 to catalog and standardize proper names for stars for the international astronomical community. It operates under Division C – Education ...

(WGSN) to catalog and standardize proper names for stars. The WGSN approved the name ''Tiaki'' for this star on 5 September 2017 and it is now so included in the List of IAU-approved Star Names. In

Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of ...

, (), meaning '' Crane'', refers to an asterism consisting of Beta Gruis,

Alpha Gruis Alpha Gruis is the brightest star in the southern constellation of Grus (constellation), Grus. It is officially named Alnair; ''Alpha Gruis'' is the star's Bayer designation, which is Latinisation of names, Latinized from α Gruis and ab ...

, Epsilon Gruis,

Eta Gruis Eta Gruis, Latinized from η Gruis, is a solitary star in the southern constellation of Grus. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.85. Based upon an annual parallax shift o ...

Delta Tucanae Delta Tucanae (δ Tuc, δ Tucanae) is a common proper motion pair located in the southwestern corner of the southern constellation of Tucana. Based upon an annual parallax shift of 13.00 mas as seen from Earth, is approximately 250 ...

Zeta Gruis Zeta Gruis, Latinised from ζ Gruis, is a solitary star in the southern constellation of Grus. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.12. Based upon an annual parallax shift ...

, Iota Gruis,

Theta Gruis Theta Gruis, Latinized from θ Gruis, is a triple star system in the southern constellation of Grus. Its combined apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object ...

, Delta² Gruis and Mu¹ Gruis. Consequently, Beta Gruis itself is known as (, en, Second Star of the Crane). The Chinese name gave rise to another English name, ''Ke''.Richard Hinckley Allen: Star Names — Their Lore and Meaning: Grus
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Properties

This is a red giant star on the asymptotic giant branch with an estimated mass of about 2.4 times that of the Sun and a surface temperature of approximately 3,480 K, just over half the surface temperature of the Sun. This low temperature accounts for the dull red color of an M-type star. The total luminosity is about 2,500 times that of the Sun, and it has estimated 180 times the Sun's radius. Beta Gruis is a

semiregular variable In astronomy, a semiregular variable star, a type of variable star, is a giant or supergiant of intermediate and late (cooler) spectral type showing considerable periodicity in its light changes, accompanied or sometimes interrupted by various irre ...

(SRb) star that varies in magnitude by about 0.4. It varies between intervals when it displays regular changes with a 37-day periodicity and times when it undergoes slow irregular variability.

References

External links

MSN Encarta

2009-10-31) {{DEFAULTSORT:Beta Gruis M-type giants Semiregular variable stars Asymptotic-giant-branch stars Grus (constellation) Gruis, Beta Durchmusterung objects 214952 112122 8636