Menu

Zuben Elgenubi

HIP 72622; Alpha2 Lib; 9 Lib

Observable Double Star Good (43/100)

Sep: 230.8", Companion: mag 5.2

HIP 72622; Alpha2 Lib; 9 Lib DoubleStar Lib Visible Level 2 Small telescope (4") - Requires steady seeing
Star Map Add to List Add to Plan
Back to Catalog

Physical Properties

Magnitude 2.75
Spectral Type A3 III/V
Star Color Yellow-white (B-V 0.15)
Distance 75.8 ly

Position & Identifiers

RA 14h 50m 52.7s
Dec -16° 02' 30.0"
Constellation Lib
HR 5531
HIP 72622
Bayer Alpha2
Flamsteed 9 Lib

Visibility

Set a location in User Settings to see visibility data.

Multiple Star System

Components 3
Component IDs O
Separation 230.8″
Companion Mag 5.2
Companion Sp F4IV
Position Angle 314°
Star Colors A: Yellow-white B: Yellow-white
Discoverer SHJ 186

Eyepiece View

32x Dawes: 1.9″ TFOV: 1.6°
Realistic = true angular size
N E 314° A (2.8) B (5.2)

Sep: 230.8″ · PA: 314° · N up, E left

Resolved · Rayleigh: 2.3″ · Dawes: 1.9″ · Eff: 3.1″

Size Comparison

Querying VizieR for stellar data…

Stellar Lifecycle

Spectral Classification

Hertzsprung-Russell Diagram

Loading HR diagram…

Blackbody Spectrum

Stellar Absorption Spectrum

Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.

Stellar Notes

CPM with HR 5530. Suspected occultation double.
Zuben Elgenubi; Zubenelgenubi; Kiffa Australis; Elkhiffa Australis.
About 2 solar radii.

Survey Image

Loading survey image…

About Zuben Elgenubi

Description

Zuben Elgenubi is a wide double star system at magnitude 2.75 in Libra, the second brightest star in the constellation. A white subgiant of spectral type A3IV, located about 77 light-years from Earth. A telescope reveals a fainter companion (magnitude 5.2) about 231 arcseconds away, making it one of the widest bright double stars in the sky.

Observing Tips

Zuben Elgenubi is the more southerly of Libra's two main stars, forming the southern pan of the Scales with Zuben Elschemali to the north. The wide companion is visible in binoculars. The pair lies between Virgo and Scorpius on the ecliptic. Best observed May through July.

History

The name Zuben Elgenubi comes from the Arabic 'al-zuban al-janubi,' meaning 'the southern claw,' from when Libra's stars were considered part of Scorpius. The Romans separated them into Libra, the only zodiacal constellation representing an inanimate object.

Fun Facts

The ecliptic passes very close to Zuben Elgenubi, making it one of the most frequently occulted bright stars. The Moon and planets regularly pass over it, and it has been used to study the lunar limb profile during occultations.