Zeta¹ Scorpii

For other stars with this Bayer designation, see Zeta Scorpii.
ζ1 Scorpii
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Scorpius
Right ascension 16h 53m 59.7269s[1]
Declination −42° 21′ 43.290″[1]
Apparent magnitude (V) 4.66 to 4.86[2]
Characteristics
Spectral type B1Iape[1]
U−B color index −0.56[3]
B−V color index +0.49[3]
Variable type SDOR:[2]
Astrometry
Radial velocity (Rv) −26.0 ± 0.9[1] km/s
Proper motion (μ) RA: −0.48[1] mas/yr
Dec.: −2.17[1] mas/yr
Distance ~5700[4] ly
(~1700 pc)
Absolute magnitude (MV) −8.7[5]
Details
Mass 60[4] M☉
Radius 52[6] R☉
Luminosity (bolometric) 1,700,000[7] L☉
Rotational velocity (v sin i) 57[3] km/s
Other designations
ζ1 Sco, Zeta1 Scorpii, Zeta1 Sco, CD−42 11633, CPD−42 7545, GC 22730, HD 152236, HIP 82671, HR 6262, PPM 322342, SAO 227375.[1]
Database references
SIMBAD data

Zeta1 Scorpii (Zeta1 Sco, ζ1 Scorpii, ζ1 Sco) is a B-type hypergiant star in the constellation of Scorpius.[1] It has an apparent visual magnitude which varies between 4.66 and 4.86.[2] It is one of the most massive stars in the Galaxy, with an estimated mass of approximately 60 solar masses, and is a member of the Scorpius OB1 association,[4] and the open star cluster NGC 6231, also known as the "northern jewel box" cluster. It is also one of the most luminous stars known in the Galaxy, with an estimated bolometric luminosity of approximately 1.7 million times the Sun's.[7]

Zeta-1 Scorpii forms a naked eye double with Zeta-2 Scorpii, but the stars are merely coincidentally near in the line of sight from Earth. Zeta-2 is a mere 155 light years distant and much less luminous in real terms. Zeta-1 Scorpii can also be distinguished from Zeta-2, due to the latter's orangeish color especially in long-exposure photographs.

References

  1. ^ a b c d e f g h HIP 82671 -- Emission-line Star, database entry, SIMBAD. Accessed on line November 20, 2009.
  2. ^ a b c zet 1 Sco, database entry, The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line November 20, 2009. (Quick look: Zet+1+Sco)
  3. ^ a b c HR 6262, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line November 20, 2009.
  4. ^ a b c Zeta-1 Sco, Stars, Jim Kaler. Accessed on line November 20, 2009.
  5. ^ p. 101, Extreme stars: at the edge of creation, James B. Kaler, Cambridge University Press, 2001, ISBN 0-521-40262-X.
  6. ^ HD 152236, database entry, Catalog of Apparent Diameters and Absolute Radii of Stars (CADARS), 3rd edition, L. E. Pasinetti-Fracassini, L. Pastori, S. Covino, and A. Pozzi, CDS ID II/224. Accessed on line November 20, 2009.
  7. ^ a b Bolometric luminosity computed from Mbol(ζ1 Sco) = −10.8 and Mbol(Sun) = 4.75. See p. 101, Extreme stars: at the edge of creation, James B. Kaler, Cambridge University Press, 2001, ISBN 0-521-40262-X.
Stars of Scorpius
Bayer
Flamsteed
Nearby
Other