When is the best time to observe Omega Aquarii?

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

Where is Omega Aquarii located in the sky?

Omega Aquarii lies in the constellation Aquarius at right ascension 23h 43m and declination -14° 33′.

What telescope do I need to split Omega Aquarii?

Splitting Omega Aquarii requires an aperture of roughly 80 mm or larger — the components are separated by about 5.3″ at magnitudes near 4.5. The companion is about 5.4 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

Omega Aquarii — Double Star in Aquarius

HIP 116971; Omega2 Aquarii; 105 Aquarii

Magnitude 4.5^m DoubleStar Aquarius (Aqr) Visible

Star Map + List + Plan

Observe

1Physical Properties

Magnitude 4.49

Spectral Type B9.5V

Star Color Blue-white (B-V -0.04)

Distance 80 ly

2Position & Identifiers

RA 23h 42m 43.3s

Dec -14° 32' 42.0"

Constellation Aquarius (Aqr)

HR 8988

HIP 116971

HD 222661

SAO 165842

Bayer Omega2

Flamsteed 105 Aqr

Double Cat 16944

SIMBAD Wikipedia

3How easy to split?

Primary 4.5 mag Companion 9.9 mag Separation 5.3″

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Telescope	Bortle 3	Bortle 4	Bortle 5
80 mm refractor 80mm refr.	V. hard+	V. hard+	V. hard+
150 mm Newton 150mm Newt.	Hard+	Hard+	Hard+
Celestron C8 (203 mm SCT) C8 203mm	Medium	Medium	Medium

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 5.3″

Companion Mag 9.9

Position Angle 82°

Star Colors A: Blue-white

Discoverer BU 279

Notes

Component B, CPM, A5Vep; however, the companion is optical.

Separation over time

Measured 1875 → 2021 (146 y)

Separation drift 5.7" → 5.3" (-0.40")

Rate -0.0027" / y

PA drift 88° → 82° (-6°, -0.041°/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.