Eta Ophiuchi

Starbox begin
name=Eta Ophiuchi A/B Starbox observe
epoch=J2000
ra=17^h 10^m 22.7^s
dec=-15° 43′ 29.7″
appmag_v=2.43 (3.0/3.5)
constell=Ophiuchus Starbox character
class=A2.5 Va/A3 V
b-v=0.05
u-b=0.09
variable=? Starbox astrometry
radial_v=-2.4
prop_mo_ra=41.16
prop_mo_dec=97.65
parallax=38.77
p_error=0.86
dist_ly=84.1
dist_pc=25.79
absmag_v=0.37 Starbox detail
mass=2.3/2.0
radius=2.5/2.0
luminosity=35/21 | temperature=8900/8600
metal=?
rotation=30 km/s.
age=? Starbox catalog
names=35 Oph, Gl 656.1A/B, HD 155125, HR 6378, BD -15°4467, GCTP 3895.00, SAO 160332, HIP 84012 Starbox reference
Simbad=HD+155125

Eta Ophiuchi (η Oph / η Ophiuchi) is a star in the constellation Ophiuchus. It also has the traditional name Sabik.

η Oph is actually a binary star system that is difficult to resolve in amateur telescopes but whose true nature has been determined through use of more advanced techniques. The "primary" star (whose observational data make up the table in this article), which could nominally be referred to as η Oph A, is actually only slightly larger and warmer than its companion, η Oph B. Individually each star is a fairly unremarkable A class main sequence star, but as a binary pair they are unusual. Each star orbits around a common center in a very fast and highly elliptical orbit, making planetary formation impossible in this system and some stellar data imprecise.