When is the best time to observe Zeta Lupi?

Zeta Lupi is best observed from April through June, with peak visibility during May when it transits around midnight in the Northern Hemisphere.

Where is Zeta Lupi located in the sky?

Zeta Lupi lies in the constellation Lupus at right ascension 15h 12m and declination -52° 06′.

What telescope do I need to split Zeta Lupi?

Splitting Zeta Lupi requires an aperture of roughly 60 mm or larger — the components are separated by about 71.7″ at magnitudes near 3.4. The companion is about 3.3 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

Zeta Lupi — Double Star in Lupus

Observable Double Star Good (51/100)

Sep: 71.7", Companion: mag 6.7

Magnitude 3.4^m DoubleStar Lupus (Lup) Visible

Star Map + List + Plan

Observe

1Physical Properties

Magnitude 3.41

Spectral Type G7III giant

Star Color Orange (B-V 0.92)

Distance 117 ly

2Position & Identifiers

RA 15h 12m 17.1s

Dec -52° 05' 57.0"

Constellation Lupus (Lup)

HR 5649

HIP 74395

HD 134505

SAO 242304

Bayer Zeta

SIMBAD

3How easy to split?

Primary 3.4 mag Companion 6.7 mag Separation 71.7″

Telescope	Bortle 3	Bortle 4	Bortle 5
80 mm refractor 80mm refr.	Easy	Easy	Easy
150 mm Newton 150mm Newt.	Easy	Easy	Easy
Celestron C8 (203 mm SCT) C8 203mm	Easy	Easy	Easy

Easy Medium Hard Very hard Impossible

Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs

4Visibility

Set a location in User Settings to see visibility data.

Best season Apr – Jun (peak: May)

5Multiple Star System

Separation 71.7″

Companion Mag 6.7

Companion Sp F8V

Position Angle 249°

Star Colors A: Orange B: Yellow

Discoverer DUN 176

Notes

CPM. B is F8. Nearly same proper motion as HR 5646, 5647.

Separation over time

Measured 1826 → 2020 (194 y)

Separation drift 69.0" → 71.7" (+2.70")

Rate +0.0139" / y

PA drift 249° → 249° (+0°, +0.000°/y)

Slow change over generations — observable in lifetime comparisons.

Measured from the WDS observational archive. No orbital solution has been derived — most likely the period is too long to fit an orbit to the available measurement arc.