When is the best time to observe Zeta Andromedae?

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

Where is Zeta Andromedae located in the sky?

Zeta Andromedae lies in the constellation Andromeda at right ascension 00h 47m and declination +24° 16′.

What telescope do I need to split Zeta Andromedae?

Splitting Zeta Andromedae requires an aperture of roughly 60 mm or larger — the components are separated by about 155.7″ at magnitudes near 4.1. The companion is about 6.7 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

Zeta Andromedae — Double Star in Andromeda

DoubleStar Andromeda (And) Visible

Star Map + List + Plan

Observe

1Physical Properties

Magnitude 4.06

Range 3.92 - 4.14

Period 17.8 days

Variable Type Ellipsoidal Variable

Spectral Type K1IIe

Star Color Orange (B-V 1.12)

Distance 88 ly

2Position & Identifiers

RA 00h 47m 20.3s

Dec +24° 16' 02.0"

Constellation Andromeda (And)

HR 215

HIP 3693

HD 4502

Bayer Zeta

Flamsteed 34 And

Variable ID Zet And

SIMBAD

3How easy to split?

Primary 4.1 mag Companion 10.8 mag Separation 155.7″

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

5Light Curve

6Multiple Star System Quadruple

Components 4 (quadruple)

Component IDs AD

Separation 155.7″

Companion Mag 10.8

Position Angle 260°

Star Colors A: Orange

Discoverer BUP 9

Notes

AB CPM. Companions probably optical.

Separation over time

Measured 1910 → 2014 (104 y)

Separation drift 167.9" → 155.7" (-12.20")

Rate -0.1173" / y

PA drift 258° → 260° (+2°, +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.