When is the best time to observe Phi Cancri?

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

Where is Phi Cancri located in the sky?

Phi Cancri lies in the constellation Cancer at right ascension 08h 27m and declination +26° 56′.

What telescope do I need to split Phi Cancri?

Splitting Phi Cancri requires an aperture of roughly 80 mm or larger — the components are separated by about 5.2″ at magnitudes near 6.3. Larger apertures and steady seeing help resolve the pair cleanly.

Phi Cancri — Double Star in Cancer

HIP 41404; Phi2 Cancri; 23 Cancri

Magnitude 6.3^m DoubleStar Cancer (Cnc) Visible

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Observe

1Physical Properties

Magnitude 6.30

Spectral Type A3V

Star Color White (B-V 0.18)

Distance 326 ly

2Position & Identifiers

RA 08h 26m 47.0s

Dec +26° 56' 07.0"

Constellation Cancer (Cnc)

HR 3311

HIP 41404

HD 71151

SAO 80188

Bayer Phi2

Flamsteed 23 Cnc

Double Cat 6815

SIMBAD Wikipedia

3How easy to split?

Primary 6.3 mag Companion 6.2 mag Separation 5.2″

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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 5.2″

Companion Mag 6.2

Companion Sp A6V

Position Angle 218°

Star Colors A: White B: Yellow-white

Discoverer STF1223

Notes

See HR 3310.

Separation over time

Measured 1782 → 2022 (240 y)

Separation drift 5.5" → 5.2" (-0.30")

Rate -0.0012" / y

PA drift 213° → 218° (+5°, +0.021°/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.