Tau Scorpii

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Template:Short descriptionScript error: No such module "Distinguish".

Tau Scorpii
Template:Location mark
Location of τ Scorpii (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Scorpius
Right ascension Template:RA[1]
Declination Template:DEC[1]
Apparent magnitude (V) +2.82[2]
Characteristics
Evolutionary stage main sequence[3]
Spectral type B0.2 V[4]
U−B Template:Engvar −1.039[2]
B−V Template:Engvar −0.252[2]
Astrometry
Radial velocity (Rv)+2.0[5] km/s
Proper motion (μ) RA: −9.89[1] mas/yr
Dec.: −22.83[1] mas/yr
Parallax (π)6.88±0.53 mas[1]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)−4.2[6]
Details
MassTemplate:Val,[7] 14.5–14.7[8] Template:Solar mass
Radius6.42[3] Template:Solar radius
Luminosity25,000[3] Template:Solar luminosity
Surface gravity (log g)4.24[9] cgs
Temperature28,862[3] K
Metallicity [Fe/H]−0.14[9] dex
Rotation41 days[10]
Rotational velocity (v sin i)24[11] km/s
Age5.22[3] Myr
Metallicity [Fe/H]{{{metal_fe2}}} dex
Other designations
Template:Odlist[12]
Database references
SIMBADdata

Script error: No such module "Check for unknown parameters".

Tau Scorpii, Latinized from τ Scorpii, formally known as Paikauhale Template:IPAc-en, is a star in the southern zodiac constellation of Scorpius. The apparent visual magnitude of Tau Scorpii is +2.8, which make it among the brightest stars of the Scorpius constellation. Parallax measurements yield a distance estimate of roughly 470 light-years (150 parsecs) from Earth.

Description

File:Tausco.jpg
Surface magnetic field of Tau Scorpii as reconstructed by means of Zeeman–Doppler imaging

Tau Scorpii is a B-type star with an early spectral classification of B0.2V.[4] It has 15 times the Sun's mass[7] and 6.4 times the radius of the Sun. It is radiating about 25,000 times the Sun's luminosity from its photosphere at an effective temperature of 28,860 K.[3] This gives it the blue-white hue characteristic of B-type stars.[13] As yet there is no evidence of a companion in orbit around τ Sco.[14] It is a magnetic star whose surface magnetic field was mapped by means of Zeeman–Doppler imaging.[15] Tau Scorpii is rotating relatively slowly with a period of 41 days.[10]

This star is 5.22 million years old, being in the main sequence. Since it is more massive than the Sun, Tau Scorpii will evolve and exhaust its core hydrogen much faster. It is expected that in around 5.38 million years it will leave the main sequence, expanding to 10.9 times the Sun's radius, and in 6.4 million years (or 11.6 Myr after its formation), it will become a red supergiant with 750 times the radius of the Sun,[3] comparable to Antares which is Template:Solar radius.[16]

The spectrum of this star shows triply ionized oxygen (O IV) that is being generated by X-rays and the Auger ionization effect. Observations with the ROSAT space telescope showed it has a higher energy (harder) X-ray spectrum than is usual for B0 V stars. Over the energy range 0.8–1.2 keV, its X-ray luminosity is Lx = 1.8 × 1031 erg s−1 with a large Lx to Lbol of log Lx/Lbol = –6.53 from ASCA measurements. ROSAT measurements showed a log Lx/Lbol ≃ –5.93 for the range 0.1–2.4 keV.[14] The hard component of the X-ray spectrum from τ Sco as studied with XMM-Newton supports the presence of in-falling clumps of plasma in τ Sco.[14]

This star is a proper motion member of the Upper Scorpius subgroup of the Scorpius–Centaurus OB association, the nearest such co-moving association of massive stars to the Sun.[6][8] The Upper Scorpius subgroup contains thousands of young stars with mean age 11 million years at average distance of 470 light years (145 parsecs).[8]

Nomenclature

τ Scorpii (Latinised to Tau Scorpii) is the star's Bayer designation.

Tau Scorpii and Sigma Scorpii together bore the traditional name Al Niyat (or Alniyat) derived from the Arabic النياط al-niyāţ "the arteries" and referring to their position flanking the star Antares, the scorpion's heart, with Tau Scorpii being the star to the south.[17]

Paikauhale is the Hawaiian name for Tau Scorpii.[18][19] It forms a line of three stars with Hōkū-‘ula (Antares) and Au-haele (σ Scorpii).[20] In the Hawaiian dictionary by Pukuʻi & Elbert (1986), the word paikauhale Script error: No such module "IPA". is defined as to go gadding about from house to house. In another Hawaiian dictionary (H.W. Kent, 1993, "Treasury of Hawaiian Words in One Hundred and One Categories", p.367), paikauhale is defined as Vagabond owning no home; house-to-house wanderer.

In 2016, the IAU organized a Working Group on Star Names (WGSN)[21] to catalog and standardize proper names for stars. The WGSN approved the name Paikauhale for the star A on 10 August 2018 and it is now so included in the List of IAU-approved Star Names.[22] The name Alniyat was given to Sigma Scorpii.

The indigenous Boorong people of northwestern Victoria saw this star (together with σ Sco) as wives of Djuit (Antares).[23]

In Chinese, Script error: No such module "Lang". (Script error: No such module "Lang".), meaning Heart, refers to an asterism consisting of τ Scorpii, σ Scorpii and Antares.[24] Consequently, the Chinese name for τ Scorpii itself is Script error: No such module "Lang". (Script error: No such module "Lang".), "the Third Star of Heart".[25]

References

Template:Reflist

Template:Sky Template:Stars of Scorpius

  1. ↑ a b c d e Cite error: Invalid <ref> tag; no text was provided for refs named aaa474_2_653
  2. ↑ a b c Cite error: Invalid <ref> tag; no text was provided for refs named apjs15_459
  3. ↑ a b c d e f g Cite error: Invalid <ref> tag; no text was provided for refs named Putra2021
  4. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named apj534_1_348
  5. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named scfs
  6. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named aaa216_1_44
  7. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named mnras410_1_190
  8. ↑ a b c Script error: No such module "Citation/CS1".
  9. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named aaa282_3_867
  10. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named aar17_3_251
  11. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named bsc1
  12. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named SIMBAD
  13. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named csiro
  14. ↑ a b c Cite error: Invalid <ref> tag; no text was provided for refs named Mewe
  15. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named mnras370_2_629
  16. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named ohnaka2013
  17. ↑ Script error: No such module "citation/CS1".
  18. ↑ Kawena, Johnson, & Ruggles, 2015, "Na Inoa Hoku: Hawaiian and Pacific Star Names", p.201
  19. ↑ Puku'i & Elbert, 1986, "Hawaiian Dictionary: Hawaiian-English, English-Hawaiian", p.31
  20. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named IAU-CSN-new
  21. ↑ Script error: No such module "citation/CS1".
  22. ↑ Script error: No such module "citation/CS1".
  23. ↑ Script error: No such module "Citation/CS1".
  24. ↑ Template:In lang 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, Template:ISBN.
  25. ↑ Template:In lang 香港太空館 - 研究資源 - 亮星中英對照表 Template:Webarchive, Hong Kong Space Museum. Accessed on line November 23, 2010.
Retrieved from "http://debianws.lexgopc.com/wiki143/index.php?title=Tau_Scorpii&oldid=1871228"