When is the best time to observe Iota Crucis?

Iota Crucis is best observed from February through April, with peak visibility during March when it transits around midnight in the Northern Hemisphere.

Where is Iota Crucis located in the sky?

Iota Crucis lies in the constellation Crux at right ascension 12h 46m and declination -60° 59′.

What telescope do I need to split Iota Crucis?

Splitting Iota Crucis requires an aperture of roughly 60 mm or larger — the components are separated by about 29.7″ at magnitudes near 4.7. The companion is about 5.5 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

Iota Crucis — Double Star in Crux

Magnitude 4.7^m DoubleStar Crux (Cru) Visible

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1Physical Properties

Magnitude 4.69

Spectral Type K0III giant

Star Color Orange (B-V 1.05)

Distance 91 ly

2Position & Identifiers

RA 12h 45m 37.9s

Dec -60° 58' 52.0"

Constellation Crux (Cru)

HR 4842

HIP 62268

HD 110829

SAO 252016

Bayer Iota

SIMBAD

3How easy to split?

Primary 4.7 mag Companion 10.2 mag Separation 29.7″

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

Easy Medium Hard Very hard Impossible

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

4Visibility

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Best season Feb – Apr (peak: Mar)

5Multiple Star System

Separation 29.7″

Companion Mag 10.2

Position Angle 2°

Star Colors A: Orange

Discoverer HJ 4547

Separation over time

Measured 1892 → 2015 (123 y)

Separation drift 27.5" → 29.7" (+2.20")

Rate +0.0179" / y

PA drift 36° → 2° (-34°, -0.276°/y)

Apparent motion is significant on a human timescale — worth revisiting in a decade.

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.