Lambda Scorpii

star system in the constellation Scorpius

Lambda Scorpii is a triple star system and the second-brightest object in the constellation of Scorpius. It is also called Shaula. Lambda Scorpii is its Bayer designation, which is translated from λ Scorpii and abbreviated Lambda Sco or λ Sco. With an apparent visual magnitude of 1.62, it is one of the brightest stars in the night sky.

λ Scorpii
Location of λ Scorpii (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Scorpius
Pronunciation /ˈʃɔːlə/[1][2]
Right ascension  17h 33m 36.520s[3]
Declination −37° 06′ 13.76″[3]
Apparent magnitude (V) 1.62 + 14.9 + 12.0[3][4]
Characteristics
Spectral type B1.5IV + B2IV[5][6]
U−B color index −0.880[7]
B−V color index −0.240[7]
Variable type Beta Cephei (A)[8]
Astrometry
Radial velocity (Rv)−3.00[9] km/s
Proper motion (μ) RA: −8.90[3][3] mas/yr
Dec.: −29.95[3] mas/yr
Parallax (π)5.71 ± 0.90[3] mas
Distanceapprox. 570 ly
(approx. 180 pc)
Absolute magnitude (MV)−3.70[10]
Orbit[11]
PrimaryA
CompanionB
Period (P)2.8825 yr
Semi-major axis (a)49.3 mas
Eccentricity (e)0.121
Inclination (i)77.2°
Orbit[11]
PrimaryAa
CompanionAb
Period (P)5.9520 d
Eccentricity (e)0.26
Semi-amplitude (K1)
(primary)
39.3 km/s
Details
λ Sco Aa
Mass10.4[5] M
Radius8.8±1.2[8] R
Luminosity36,300[8] L
Surface gravity (log g)3.8[6] cgs
Temperature25,000±1,000[8] K
Rotation3.4±0.5 d[8]
Rotational velocity (v sin i)150[8] km/s
λ Sco B
Mass8.1[5] M
Radius4.7±1.0[8] R
Surface gravity (log g)4.0[6] cgs
Temperature25,000±1,000[8] K
λ Sco Ab
Mass1.8[5] M
Other designations
Shaula, 35 Scorpii, 35 Sco, CD−37 11673, FK5 652, HD 158926, HIP 85927, HR 6527, SAO 208954, CCDM J17336-3706A/B/C
Database references
SIMBADdata

References

change
  1. Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN 978-1-931559-44-7.
  2. "IAU Catalog of Star Names". Retrieved 28 July 2016.
  3. 3.0 3.1 3.2 3.3 3.4 3.5 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
  4. Reed, B. Cameron (2003), "Catalog of Galactic OB Stars", The Astronomical Journal, 125 (5): 2531–2533, Bibcode:2003AJ....125.2531R, doi:10.1086/374771.
  5. 5.0 5.1 5.2 5.3 Tango, W. J.; Davis, J.; Ireland, M. J.; Aerts, C.; Uytterhoeven, K.; Jacob, A. P.; Mendez, A.; North, J. R.; Seneta, E. B.; Tuthill, P. G. (2006). "Orbital elements, masses and distance of λ Scorpii a and B determined with the Sydney University Stellar Interferometer and high-resolution spectroscopy". Monthly Notices of the Royal Astronomical Society. 370 (2): 884–890. arXiv:astro-ph/0605311. Bibcode:2006MNRAS.370..884T. doi:10.1111/j.1365-2966.2006.10526.x. S2CID 13971499.
  6. 6.0 6.1 6.2 Uytterhoeven, K.; Willems, B.; Lefever, K.; Aerts, C.; Telting, J. H.; Kolb, U. (2004). "Interpretation of the variability of the β Cephei star λ Scorpii". Astronomy and Astrophysics. 427 (2): 581–592. Bibcode:2004A&A...427..581U. doi:10.1051/0004-6361:20041223. hdl:2066/60554.
  7. 7.0 7.1 Hamdy, M. A.; Abo Elazm, M. S.; Saad, S. M. (1993). "A catalogue of spectral classification and photometric data of B-type stars". Astrophysics and Space Science. 203 (1): 53–107. Bibcode:1993Ap&SS.203...53H. doi:10.1007/BF00659414. S2CID 122459090.
  8. 8.0 8.1 8.2 8.3 8.4 8.5 8.6 8.7 Handler, G.; Schwarzenberg-Czerny, A. (2013). "Time-resolved multicolour photometry of bright B-type variable stars in Scorpius". Astronomy & Astrophysics. 557: A1. arXiv:1307.2733. Bibcode:2013A&A...557A...1H. doi:10.1051/0004-6361/201321886. S2CID 56403146.
  9. Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
  10. Balona, L. A.; Feast, M. W. (1975). "The luminosities of the beta Canis Majoris variables, the zero age main sequence and the distance of the Sco-Cen association". Monthly Notices of the Royal Astronomical Society. 172 (1): 191–203. Bibcode:1975MNRAS.172..191B. doi:10.1093/mnras/172.1.191.
  11. 11.0 11.1 Tokovinin, Andrei (2018-03-01). "The Updated Multiple Star Catalog". The Astrophysical Journal Supplement Series. 235 (1): 6. arXiv:1712.04750. Bibcode:2018ApJS..235....6T. doi:10.3847/1538-4365/aaa1a5. ISSN 0067-0049. S2CID 119047709.