Kappa Scorpii

Coordinates: Sky map 17h 42m 29.27520s, −39° 01′ 47.9391″
Source: Wikipedia, the free encyclopedia.
κ Scorpii
Location of κ Sco (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Scorpius
Right ascension 17h 42m 29.27520s[1]
Declination −39° 01′ 47.9391″[1]
Apparent magnitude (V) 2.41 - 2.42[2]
Characteristics
Spectral type B1.5 III[3]
U−B color index −0.914[4]
B−V color index −0.228[4]
Variable type β Cephei[2]
Distance
480 ± 10 ly
(148 ± 4 pc)
Absolute magnitude (MV)−3.46[6]
Semi-amplitude
(K1)
(primary)		48.0±0.3 km/s
Details
κ Sco A
Myr
κ Sco B
Mass12[7] M☉
Radius5.8[7] R☉
Surface gravity (log g)4.00[7] cgs
Temperature18,800[7] K
HR 6580, SAO
 209163
Database references
SIMBADdata

Kappa Scorpii,

apparent visual magnitude of 2.4, this star system is readily visible to the naked eye. Parallax measurements place it at an estimated distance of roughly 480 light-years (150 parsecs) from the Earth
.

Properties

This is a

luminosity class indicates the presence of a giant star that has exhausted the supply of hydrogen at its core and is in a late evolutionary stage
.

A light curve for Kappa Scorpii, adapted from Lomb and Shobbrook (1975)[10]

The primary component of the pair, κ Sco A, is a variable star of Beta Cephei type. It is undergoing radial pulsations with a dominant frequency of 4.99922 cycles per day, or 4.8 hours per cycle. There are overlapping secondary pulsation frequencies of about 4.85 and 5.69 cycles per day.[11] This star has about 17 times the mass of the Sun and is nearly 7 times the Sun's radius.[7] The effective temperature of the outer envelope is 23,400 K,[7] giving it a blue-white hue. It is rotating rapidly, with an estimated period of only 1.9 days and an axis of rotation that is inclined by about 40° to the line of sight from the Earth.[7]

The secondary component, κ Sco B, is smaller than the primary, but still much larger than the Sun. It has about 12 times the mass of the Sun and nearly six times the Sun's radius.[7] The effective temperature of 18,800 K[7] is also higher than the Sun's, which is at 5,778 K.

Traditional name

κ Scorpii has been called Girtab /ˈɡɜːrtæb/,[12] which is the Sumerian word for 'scorpion'. The name has survived through the Babylonian star catalogues,[13] and was originally applied to an asterism comprising this star, Lambda Scorpii, Upsilon Scorpii, and Iota Scorpii.[12]

In

Chinese name for κ Scorpii itself is 尾宿七 (Wěi Xiù qī), "the Seventh Star of Tail".[15]

Modern legacy

κ Scorpii appears on the flag of Brazil, symbolising the state of Paraíba.[16]

References

  1. ^
    S2CID 18759600
  2. ^
    S2CID 125853869
    .
  3. ^
    Bibcode:1982mcts.book.....H
  4. ^
    doi:10.1086/190168
  5. Bibcode:1999VeARI..35....1W
  6. ^
    S2CID 119257644
    .
  7. ^
    doi:10.1051/0004-6361:20010456
  8. Bibcode:1970CoAsi.239....1B
  9. S2CID 118629873
  10. doi:10.1093/mnras/173.3.709
    . Retrieved 18 August 2022.
  11. hdl:2066/32420
  12. ^
    ISBN 978-1-4614-0136-0
  13. ISBN 0-7188-2695-7
  14. ISBN 978-986-7332-25-7
    .
  15. ^ (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表 Archived 2008-10-25 at the Wayback Machine, Hong Kong Space Museum. Accessed on line November 23, 2010.
  16. ^ "Astronomy of the Brazilian Flag". FOTW Flags Of The World website.

External links

  • Kaler, James B., "Kappa Sco", Stars, University of Illinois, retrieved 2014-02-18


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