When is the best time to observe Mu Andromedae?

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

Where is Mu Andromedae located in the sky?

Mu Andromedae lies in the constellation Andromeda at right ascension 00h 57m and declination +38° 30′.

What telescope do I need to split Mu Andromedae?

Splitting Mu Andromedae requires an aperture of roughly 60 mm or larger — the components are separated by about 260.0″ at magnitudes near 3.9. The companion is about 7.2 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

Mu Andromedae — Double Star in Andromeda

DoubleStar Andromeda (And) Visible

Star Map + List + Plan

Observe

1Physical Properties

Magnitude 3.87

Spectral Type A6V

Star Color White (B-V 0.13)

Distance 130 ly

2Position & Identifiers

RA 00h 56m 45.2s

Dec +38° 29' 58.0"

Constellation Andromeda (And)

HR 269

HIP 4436

HD 5448

Bayer Mu

Flamsteed 37 And

Double Cat 788

SIMBAD

3How easy to split?

Primary 3.9 mag Companion 11.0 mag Separation 260.0″

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Telescope	Bortle 3	Bortle 4	Bortle 5
80 mm refractor 80mm refr.	Hard+	Hard	V. hard+
150 mm Newton 150mm Newt.	Medium+	Medium	Medium
Celestron C8 (203 mm SCT) C8 203mm	Easy	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 Quadruple C,D: optical

Components 4 (quadruple)

Component IDs AD

Separation 260.0″

Companion Mag 11.0

Position Angle 39°

Star Colors A: White

Discoverer HJ 1057

Notes

All components optical.

Separation over time

Measured 1854 → 2012 (158 y)

Separation drift 277.4" → 260.0" (-17.40")

Rate -0.1101" / y

PA drift 42° → 39° (-3°, -0.019°/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.