When is the best time to observe 55 Piscium?

55 Piscium is best observed from August through October, with peak visibility during September when it transits around midnight in the Northern Hemisphere.

Where is 55 Piscium located in the sky?

55 Piscium lies in the constellation Pisces at right ascension 00h 40m and declination +21° 26′.

What telescope do I need to split 55 Piscium?

Splitting 55 Piscium requires an aperture of roughly 80 mm or larger — the components are separated by about 6.8″ at magnitudes near 5.4. The companion is about 3.1 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

55 Piscium — Double Star in Pisces

Observable Double Star Excellent (60/100)

Sep: 6.8", Companion: mag 8.5

Magnitude 5.4^m DoubleStar Pisces (Psc) Visible

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Observe

1Physical Properties

Magnitude 5.36

Spectral Type K0III+F3V giant

Star Color Red (B-V 1.16)

Distance 362 ly

2Position & Identifiers

RA 00h 39m 55.6s

Dec +21° 26' 18.0"

Constellation Pisces (Psc)

HR 167

HIP 3138

HD 3690

SAO 74182

Flamsteed 55 Psc

Double Cat 558

SIMBAD

3How easy to split?

Primary 5.4 mag Companion 8.5 mag Separation 6.8″

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Telescope	Bortle 3	Bortle 4	Bortle 5
80 mm refractor 80mm refr.	Easy	Easy	Medium+
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 Aug – Oct (peak: Sep)

5Multiple Star System

Separation 6.8″

Companion Mag 8.5

Companion Sp F3V

Position Angle 195°

Star Colors A: Red B: Yellow-white

Discoverer STF 46

Notes

Binary.

Separation over time

Measured 1830 → 2023 (193 y)

Separation drift 6.4" → 6.8" (+0.40")

Rate +0.0021" / y

PA drift 193° → 195° (+2°, +0.010°/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.