When is the best time to observe 51 Piscium?

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

Where is 51 Piscium located in the sky?

51 Piscium lies in the constellation Pisces at right ascension 00h 32m and declination +06° 57′.

What telescope do I need to split 51 Piscium?

Splitting 51 Piscium requires an aperture of roughly 60 mm or larger — the components are separated by about 27.0″ at magnitudes near 5.7. The companion is about 3.8 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

51 Piscium — Double Star in Pisces

Magnitude 5.7–9.0^m DoubleStar Pisces (Psc) Visible

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Observe

1Physical Properties

Magnitude 5.67

Range 5.67 - 9.00

Variable Type E:

Spectral Type B9.5V

Star Color Blue-white (B-V 0.00)

2Position & Identifiers

RA 00h 32m 23.8s

Dec +06° 57' 20.0"

Constellation Pisces (Psc)

HR 132

HIP 2548

HD 2913

SAO 109262

Flamsteed 51 Psc

Variable ID Var?

Double Cat 449

SIMBAD

3How easy to split?

Primary 5.7 mag Companion 9.5 mag Separation 27.0″

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Telescope	Bortle 3	Bortle 4	Bortle 5
80 mm refractor 80mm refr.	Medium+	Medium+	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 Quadruple C: optical

Components 4 (quadruple)

Component IDs O

Separation 27.0″

Companion Mag 9.5

Position Angle 84°

Star Colors A: Blue-white B: Yellow-white

Discoverer STF 36

Notes

ADS 449A is triple occultation system, 6.2, 6.9v, sep. 0.031"; third component 8.8v at 0.196". ADS 449B, 9.7v at 27.5". | AB are CPM.

Separation over time

Measured 1782 → 2018 (236 y)

Separation drift 22.5" → 27.0" (+4.50")

Rate +0.0191" / y

PA drift 89° → 84° (-5°, -0.021°/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.