It bore the traditional name Sabik, from the Arabic السابق al-sābiq "the preceding one", of uncertain reference.[9] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[12] to catalogue and standardize proper names for stars. The WGSN approved the name Sabik for the component WDS J17104-1544 A on 21 August 2016 and it is now so included in the List of IAU-approved Star Names.[10]
Eta Ophiuchi consists of two A-type main-sequence stars,[4] currently fusing hydrogen into helium at their core. The primary, of apparent magnitude +3.05,[3] has about 2.5 times the Sun's radius and 2.25 times its mass, with an effective temperature around 9,000 K.[4] The secondary, of apparent magnitude +3.27,[3] is 2 times as large and massive than the Sun, with an effective temperature of 8,700 K. The estimated age of the system is 500 million years, albeit with significant uncertainty.[4]
The stars take 87.8 years to complete an orbit, which is highly elliptical: While the semi-major axis is 31 astronomical units, the high orbital eccentricity of 0.931 take them to a distance of 2.15 au during their closest approach (the periastron); the last of such occurring in 2024. Such large eccentricity hindered accurate measurements of the stellar mass with the Kepler's third law, until observations with the Very Large Telescope during the most recent periastron accurately determined orbital elements such as the eccentricity, hence a considerable mass sum for A2V-type stars.[4]
^ abSabik. stars.astro.illinois.edu. Retrieved July 1, 2024.
^ abGray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Bubar, E. J.; McGahee, C. E.; O'Donoghue, A. A.; Knox, E. R. (2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc--The Southern Sample". The Astronomical Journal. 132 (1): 161–170. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637. S2CID119476992.
^ abKunitzsch, 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. ISBN978-1-931559-44-7.
^Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv:1012.0707 [astro-ph.SR].
