Tau Scorpii

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Star
τ Scorpii
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation Scorpio
Right ascension 16 h 35 m 53 s
declination -28 ° 12 ′ 58 ″
Apparent brightness 2.81 mag
Typing
B − V color index −0.25 
U − B color index −1.01 
R − I index -0.25 
Spectral class B0.2 V
Astrometry
Radial velocity (+2.0 ± 0.9) km / s
parallax (6.88 ± 0.53)  mas
distance (470 ± 40)  ly
(145 ± 11)  pc
Proper movement 
Rec. Share: (−9.89 ± 0.61)  mas / a
Dec. portion: (−22.83 ± 0.55)  mas / a
Physical Properties
Dimensions (17)  M ☉
Luminosity

(25000)  L ☉

Effective temperature (32000)  K
Other names
and catalog entries
Bayer name τ Scorpii
Flamsteed name 23 Scorpii
Cordoba Survey CD −27 ° 11015
Bright Star Catalog HR 6165 [1]
Henry Draper Catalog HD 149438 [2]
Hipparcos catalog HIP 81266 [3]
SAO catalog SAO 184481 [4]
Tycho catalog TYC 6807-1012-1 [5]
2MASS catalog 2MASS J16355295-2812576 [6]
Other names Al Niyat, Paikauhale, FK5  620

τ Scorpii ( Tau Scorpii , τ Sco ) is a star in Scorpio . Its distance is around 500 light years .

Together with σ Scorpii , the star was named Alniyat / Al Niyat ( Arabic النياط, DMG an-niyāṭ ).

The analysis of the spectrum of τ Scorpii by Albrecht Unsöld , taken in 1939 during a visit to the Yerkes and McDonald observatories , provided the first detailed analysis of a star other than the sun .

The star is a blue straggler and has an exceptionally strong magnetic field . It is believed that Tau Scorpii could be the result of a star collision . In 2019, a research group was able to use a simulation to show that the special magnetic properties of Tau Scorpii could actually be attributed to such a merging of two stars. The starting point for the simulation was the collision of two stars with eight or nine times the mass of the sun . According to the simulation, the collision of the stars leads to the formation of an accretion disk , which orbits the newly formed star. The high speed of the particles in the star and accretion disk creates strong magnetic fields. Magnetic fields created in this way can possibly persist for so long that they persist even after a supernova . Tau Scorpii, as a newly formed neutron star , might still have an extremely strong magnetic field, i.e. it would be a magnetar .

Representation of the magnetic field lines of Tau Scorpii

Web links

Individual evidence

  1. ↑ a b c d e f g h i tau Sco. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed December 8, 2018 .
  2. ↑ a b c d e Fabian RN Schneider, Sebastian T. Ohlmann, Philipp Podsiadlowski, Friedrich K. Röpke, Steven A. Balbus, Rüdiger Pakmor, Volker Springel: Stellar mergers as the origin of magnetic massive stars . In: Nature . No. 574, 2019, pp. 211-214. doi : 10.1038 / s41586-019-1621-5 .
  3. ^ Robert Gast: 70 year old riddle solved: The origin of the magnetars. Spektrum.de , October 11, 2019, accessed on October 12, 2019 .