When is the best time to observe Mu Aquilae?

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

Where is Mu Aquilae located in the sky?

Mu Aquilae lies in the constellation Aquila at right ascension 19h 34m and declination +07° 23′.

What telescope do I need to split Mu Aquilae?

Splitting Mu Aquilae requires an aperture of roughly 60 mm or larger — the components are separated by about 165.9″ at magnitudes near 4.5. The companion is about 5.1 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

Mu Aquilae — Double Star in Aquila

DoubleStar Aquila (Aql) Visible

Star Map + List + Plan

Observe

1Physical Properties

Magnitude 4.45

Spectral Type K3-IIIbCN0.5

Star Color Red (B-V 1.17)

Distance 72 ly

2Position & Identifiers

RA 19h 34m 05.4s

Dec +07° 22' 44.0"

Constellation Aquila (Aql)

HR 7429

HIP 96229

HD 184406

Bayer Mu

Flamsteed 38 Aql

Double Cat 12607

SIMBAD

3How easy to split?

Primary 4.5 mag Companion 9.6 mag Separation 165.9″

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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 Jun – Aug (peak: Jul)

5Multiple Star System Sextuple B,C: optical

Components 6 (sextuple)

Component IDs AE

Separation 165.9″

Companion Mag 9.6

Position Angle 62°

Star Colors A: Red

Discoverer BU 653

Notes

B and C optical.

Separation over time

Measured 1887 → 2012 (125 y)

Separation drift 183.1" → 165.9" (-17.20")

Rate -0.1376" / y

PA drift 72° → 62° (-10°, -0.080°/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.