When is the best time to observe Psi Cygni?

Psi Cygni is best observed from June through August, with peak visibility during July when it transits around midnight in the Northern Hemisphere.

Where is Psi Cygni located in the sky?

Psi Cygni lies in the constellation Cygnus at right ascension 19h 56m and declination +52° 26′.

What telescope do I need to split Psi Cygni?

Splitting Psi Cygni requires an aperture of roughly 100 mm or larger — the components are separated by about 2.8″ at magnitudes near 4.9. Larger apertures and steady seeing help resolve the pair cleanly.

Psi Cygni — Double Star in Cygnus

Observable Double Star Good (52/100)

Sep: 2.8", Companion: mag 7.5

Magnitude 4.9^m DoubleStar Cygnus (Cyg) Visible

Star Map + List + Plan

Observe

1Physical Properties

Magnitude 4.92

Spectral Type A4Vn

Star Color White (B-V 0.12)

Distance 652 ly

2Position & Identifiers

RA 19h 55m 37.8s

Dec +52° 26' 20.0"

Constellation Cygnus (Cyg)

HR 7619

HIP 98055

HD 189037

SAO 32114

Bayer Psi

Flamsteed 24 Cyg

Double Cat 13148

SIMBAD

3How easy to split?

Primary 4.9 mag Companion 7.5 mag Separation 2.8″

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Telescope	Bortle 3	Bortle 4	Bortle 5
80 mm refractor 80mm refr.	Hard+	Hard+	Hard+
150 mm Newton 150mm Newt.	Medium+	Medium+	Medium+
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 Jun – Aug (peak: Jul)

5Multiple Star System Quadruple D: optical

Components 4 (quadruple)

Component IDs AB

Separation 2.8″

Companion Mag 7.5

Position Angle 175°

Star Colors A: White B: Yellow-white

Discoverer STF2605

Notes

AB combined mag., colors. Sources differ on spectral class of component B from A7V to F4V. vsini of B, 120k/s.

Separation over time

Measured 1822 → 2021 (199 y)

Separation drift 3.6" → 2.8" (-0.80")

Rate -0.0040" / y

PA drift 187° → 175° (-12°, -0.060°/y)

Slow change over generations — observable in lifetime comparisons.

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.