Lambda Scorpii

Starbox begin
name=Lambda Scorpii A/B/C Starbox observe
epoch=J2000.0
constell=Scorpius
ra=17^h 33^m 36.6^s / 42.6^s / 32.5^s
dec=-37° 06′ 13″ /
-37° 06′ 44″ /
-37° 04′ 52″
appmag_v=1.62 / 14.9 / 12.0 Starbox character
class=B1.5-2 IV+ (A)
b-v=-0.23 (A)
u-b=-0.91 (A)
variable=Beta Cephei (A) Starbox astrometry
component_name=(component A)
radial_v=-3
prop_mo_ra=-8.90
prop_mo_dec=-29.95
parallax=4.64
p_error=0.90
absmag_v=-5 Starbox catalog
names=Shaula, 35 Scorpii, 35 Sco, HR 6527, CD -37 11673, HD 158926,SAO 208954, FK5 652, HIP 85927, CCDM J17336-3706A/B/C.

Lambda Scorpii (λ Sco / λ Scorpii) is the second brightest star system in the constellation Scorpius, and one of the brightest stars in the nighttime sky. It has the Bayer designation λ despite being the second brightest in its constellation. It also has the traditional name Shaula, which comes from the Arabic الشولاء "al-šawlā´" meaning "the raised [tail] ", as it is found in the tail of the scorpion (Scorpius). It is known as 尾宿八 (the Eighth Star of the Tail) in Chinese.

Lambda Scorpii is a multiple star with three visible components. The first,Lambda Scorpii A, is classified as a B-type subgiant. The 15th
magnitude Lambda Scorpii B has a separation of 42 arcseconds from component A,while the 12th magnitude Lambda Scorpii C is 95 arcseconds from A. It is not known whether or notthese components are physically associated with component A. If they both were, B would be approximately 7500 Astronomical Units and C approximately 17,000 AU (0.27 light years) from A.

Spectroscopic and interferometric observationshave shown that A is actually a triple system consisting of two B-typestars and a pre-main sequence star. The primary star is also a beta Cephei variable star. [Interpretation of the variability of the β Cephei star λ Scorpii. I. The multiple character, K. Uytterhoeven, B. Willems, K. Lefever, C. Aerts, J. H. Telting, and U. Kolb, "Astronomy and Astrophysics" 427 (2004), 581–592. [http://adsabs.harvard.edu/abs/2004A&A...427...581 Abstract on ADSABS] ] [ Orbital elements, masses and distance of λ Scorpii A and B determined with the Sydney University Stellar Interferometer and high-resolution spectroscopy, W. J. Tango, J. Davis, M. J. Ireland, C. Aerts, K. Uytterhoeven, A. P. Jacob, A. Mendez, J. R. North, E. B. Seneta, and P. G. Tuthill, "Monthly Notices of the Royal Astronomical Society" 370 (2006) 884–890. [http://adsabs.harvard.edu/abs/2006MNRAS.370..884T Abstract on ADSABS] ] The pre-main sequence star has an orbital period of 6 days and the B companion has a period of 1053 days. The three stars lie in the same orbital plane, strongly suggesting that they were formed at the same time. The masses of the primary, pre-main sequence star and the B companion are10.4±1.3, 1.8±0.2 and 8.1±1.0 solar masses, respectively. The age of the system is estimated to be in the range 10–13 million years.

The interferometric and spectroscopic observations allow the distance to the system to be determined independently of other methods. Its distance is 112±5 parsecs.

Trivia

*The fictional planet of Cybertron (in "The Transformers" comics continuity by IDW Publishing) orbits Lambda Scorpii (or, "Shaula").

References

External links

* [http://www.astro.uiuc.edu/~kaler/sow/shaula.html Shaula at Jim Kaler's STARS]