Beta Boötis

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Beta Boötis
A star chart showing the position of β Boötis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation
Boötes
Right ascension 15h 01m 56.76238s[1]
Declination +40° 23′ 26.0406″[1]
Apparent magnitude (V) 3.488[2]
Characteristics
Spectral type G8IIIa[3]
U−B color index +0.75[2]
B−V color index +0.94[2]
Variable type Flare star[4]
Distance
225 ± 2 ly
(69.1 ± 0.7 pc)
Absolute magnitude (MV)–0.70[6]
Details
Myr
HR 5602, SAO 45337[3]
Database references
SIMBADdata

Beta Boötis,

apparent visual magnitude of 3.5,[2] making it one of the brighter members of the constellation. In the modern constellation, it marks the head of Boötis the herdsman.[8] Based upon parallax measurements obtained during the Hipparcos mission, this star is approximately 225 light-years (69 parsecs) from the Sun.[1] At that distance, the magnitude of the star is reduced by 0.06 from extinction caused by intervening gas and dust.[6]

Nomenclature

β Boötis (Latinised to Beta Boötis) is the star's Bayer designation.

It bore the traditional name Nekkar or Nakkar derived from the Arabic name for the constellation: Al Baḳḳār 'the Herdsman'.[8] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[9] to catalogue and standardize proper names for stars. The WGSN approved the name Nekkar for this star on 21 August 2016 and it is now so included in the List of IAU-approved Star Names.[7]

Properties

Nakkar has more than three times the

G-type star. It has an estimated rotation period of about 200 days and the pole is inclined 28° ± 6° to the line of sight from the Earth.[4]

In 1993, the ROSAT satellite was used to observe an X-ray flare on Beta Boötis, which released an estimated 1.7 × 1032 erg. This was the first such observation for a low-activity star of this type. The flare may be explained by an as yet unobserved M-type dwarf companion star.[11]

References

  1. ^
    S2CID 18759600
    .
  2. ^
    doi:10.1086/190856
  3. ^
    Centre de Données astronomiques de Strasbourg
    , retrieved 2011-11-28
  4. ^
    S2CID 16676999
  5. ^
    doi:10.1088/0004-6256/135/1/209
  6. ^
    S2CID 16258166
  7. ^ a b "Naming Stars". IAU.org. Retrieved 7 March 2018.
  8. ^
    Allen, Richard Hinckley (1899), Star-names and their meanings
    , G. E. Stechert, p. 103, retrieved 2011-11-28
  9. ^ IAU Working Group on Star Names (WGSN), International Astronomical Union, retrieved 22 May 2016.
  10. S2CID 118629873
  11. Bibcode:1995A&A...296..509H

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Beta_Boötis&oldid=1170090032"