When is the best time to observe Iota Cancri?

Iota Cancri is best observed from December through February, with peak visibility during January when it transits around midnight in the Northern Hemisphere.

Where is Iota Cancri located in the sky?

Iota Cancri lies in the constellation Cancer at right ascension 08h 47m and declination +28° 46′.

What telescope do I need to split Iota Cancri?

Splitting Iota Cancri requires an aperture of roughly 60 mm or larger — the components are separated by about 30.6″ at magnitudes near 4.0. Larger apertures and steady seeing help resolve the pair cleanly.

Iota Cancri — Double Star in Cancer

HIP 43103; Iota Cancri; 48 Cancri

Observable Double Star Excellent (70/100)

Sep: 30.6", Companion: mag 6.0

Magnitude 4.0^m DoubleStar Cancer (Cnc) Visible

Star Map + List + Plan

Observe

1Physical Properties

Magnitude 4.02

Spectral Type G7.5IIIaBa0.1 bright giant

Star Color Orange (B-V 1.01)

Distance 192 ly

2Position & Identifiers

RA 08h 46m 41.8s

Dec +28° 45' 36.0"

Constellation Cancer (Cnc)

HR 3475

HIP 43103

HD 74739

SAO 80416

Bayer Iota

Flamsteed 48 Cnc

Double Cat 6988

SIMBAD Wikipedia

3How easy to split?

Primary 4.0 mag Companion 6.0 mag Separation 30.6″

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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

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Best season Dec – Feb (peak: Jan)

5Multiple Star System

Separation 30.6″

Companion Mag 6.0

Companion Sp A2V

Position Angle 308°

Star Colors A: Orange B: White

Discoverer STF1268

Notes

Binary with HR 3474.

Separation over time

Measured 1777 → 2021 (244 y)

Separation drift 31.0" → 30.6" (-0.40")

Rate -0.0016" / y

PA drift 302° → 308° (+6°, +0.025°/y)

Essentially fixed on human timescales — the same view your grandchildren will see.

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.