Saiph

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Star
Saiph
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation Orion
Right ascension 05 h 47 m 45.39 s
declination -09 ° 40 ′ 10.6 ″
Apparent brightness 2.07 mag
Typing
B − V color index −0.17 
U − B color index −1.03 
R − I index −0.18 
Spectral class B0.5 Iavar
Astrometry
Radial velocity (20.9 ± 2.3) km / s
parallax (5.04 ± 0.22)  mas
distance (647 ± 28)  ly
(198.4 ± 8.7)  pc  
Visual absolute brightness M vis −4.42 mag
Proper movement 
Rec. Share: (1.46 ± 0.17)  mas / a
Dec. portion: (−1.28 ± 0.13)  mas / a
Physical Properties
Dimensions 15–17  M ☉
radius approx. 11  R ☉
Luminosity

6,200  L ☉

Effective temperature 26,000  K
Other names
and catalog entries
Bayer name κ Orionis
Flamsteed name 53 Orionis
Bonn survey BD -09 ° 1235
Bright Star Catalog HR 2004 [1]
Henry Draper Catalog HD 38771 [2]
Hipparcos catalog HIP 27366 [3]
SAO catalog SAO 132542 [4]
Tycho catalog TYC 5351-760-1 [5]
2MASS catalog 2MASS J05474538-0940105 [6]
Other names Saiph, FK5 220
annotation
  1. ↑ Calculated from apparent brightness and distance.

Saiph ( Arabic سيف, DMG saif  'sword'; actually saif al-dschabbār "sword of the giant") is the proper name of the star κ Orionis (Kappa Orionis). The name refers to the fact that the Arab astronomers saw a giant in Orion; Saiph was actually another star (namely Eta Orionis ), but the transmission error was retained. From our point of view, he is Orion's footstep to the east. Its Flamsteed name is 53 Orionis. Saiph is the sixth brightest star in the constellation, with the second magnitude class ( apparent magnitude of 2.07 mag) easily recognizable with the naked eye. Its distance was overestimated before the new determination by the Hipparcos satellite, according to which Saiph is "only" about 650 light years away from the sun. It is a blue giant and belongs to spectral class B0 and luminosity class Ia. Despite its great luminosity, it appears paler than the similarly distant Rigel , as it emits a large part of its radiation in the invisible ultraviolet spectral range. Its bolometric brightness is 65,000 times greater than that of the sun, in the visible range its luminosity is more than 6000 times that of the sun. As far as we know today, Saiph is a single star.

See also

Individual evidence

  1. ↑ a b c Hipparcos catalog (ESA 1997)
  2. ↑ a b c Bright Star Catalog
  3. ↑ Pulkovo radial velocities for 35493 HIP stars
  4. ↑ a b c Hipparcos, the New Reduction (van Leeuwen, 2007)
  5. ↑ a b c Saiph. Jim Kaler, accessed September 26, 2018 .