When is the best time to observe Chi Ceti?

Chi Ceti is best observed from September through November, with peak visibility during October when it transits around midnight in the Northern Hemisphere.

Where is Chi Ceti located in the sky?

Chi Ceti lies in the constellation Cetus at right ascension 01h 50m and declination -10° 41′.

What telescope do I need to split Chi Ceti?

Splitting Chi Ceti requires an aperture of roughly 60 mm or larger — the components are separated by about 184.1″ at magnitudes near 4.7. Larger apertures and steady seeing help resolve the pair cleanly.

Chi Ceti — Double Star in Cetus

Observable Double Star Good (47/100)

Sep: 184.1", Companion: mag 6.8

Magnitude 4.7^m DoubleStar Cetus (Cet) Visible

Star Map + List + Plan

Observe

1Physical Properties

Magnitude 4.67

Spectral Type F3III giant

Star Color Yellow-white (B-V 0.33)

Distance 71 ly

2Position & Identifiers

RA 01h 49m 35.1s

Dec -10° 41' 11.0"

Constellation Cetus (Cet)

HR 531

HIP 8497

HD 11171

SAO 148036

Bayer Chi

Flamsteed 53 Cet

SIMBAD

3How easy to split?

Primary 4.7 mag Companion 6.8 mag Separation 184.1″

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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 Sep – Nov (peak: Oct)

5Multiple Star System

Separation 184.1″

Companion Mag 6.8

Companion Sp G3V

Position Angle 250°

Star Colors A: Yellow-white B: Yellow

Discoverer ENG 8

Notes

CPM. Companion, dG1 is HD 11131.

Separation over time

Measured 1888 → 2016 (128 y)

Separation drift 183.9" → 184.1" (+0.20")

Rate +0.0016" / y

PA drift 250° → 250° (+0°, +0.000°/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.