When is the best time to observe 12 Aquarii?

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

Where is 12 Aquarii located in the sky?

12 Aquarii lies in the constellation Aquarius at right ascension 21h 04m and declination -05° 49′.

What telescope do I need to split 12 Aquarii?

Splitting 12 Aquarii requires an aperture of roughly 100 mm or larger — the components are separated by about 2.4″ at magnitudes near 5.9. Larger apertures and steady seeing help resolve the pair cleanly.

12 Aquarii — Double Star in Aquarius

Observable Double Star Good (56/100)

Sep: 2.4", Companion: mag 7.5

Magnitude 5.9^m DoubleStar Aquarius (Aqr) Visible

Star Map + List + Plan Star Hop

Observe

1Physical Properties

Magnitude 5.89

Spectral Type G4III giant

Star Color Orange (B-V 0.68)

Distance 1,087 ly

2Position & Identifiers

RA 21h 04m 04.7s

Dec -05° 49' 23.0"

Constellation Aquarius (Aqr)

HR 8059

HIP 103981

HD 200496

SAO 145064

Flamsteed 12 Aqr

Double Cat 14592

SIMBAD

3How easy to split?

Primary 5.9 mag Companion 7.5 mag Separation 2.4″

Sign in and configure your equipment and default location to see a personalized row.

Telescope	Bortle 3	Bortle 4	Bortle 5
80 mm refractor 80mm refr.	Hard+	Hard+	Hard+
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

Set a location in User Settings to see visibility data.

Best season Jul – Sep (peak: Aug)

5Multiple Star System Triple

Components 3 (triple)

Separation 2.4″

Companion Mag 7.5

Position Angle 198°

Star Colors A: Orange B: Orange

Discoverer STF2745

Notes

CPM with HR 8058. Colors for combined light. Mag. for blend 5.54V. Measured sep. Aa 1985.5 0.045" by speckle | interferometry.

Separation over time

Measured 1825 → 2021 (196 y)

Separation drift 3.2" → 2.4" (-0.80")

Rate -0.0041" / y

PA drift 192° → 198° (+6°, +0.031°/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.