When is the best time to observe 1 Arietis?

1 Arietis is best observed from September through November, with peak visibility during October when it transits around midnight in the Northern Hemisphere.

Where is 1 Arietis located in the sky?

1 Arietis lies in the constellation Aries at right ascension 01h 50m and declination +22° 17′.

What telescope do I need to split 1 Arietis?

Splitting 1 Arietis requires an aperture of roughly 100 mm or larger — the components are separated by about 2.9″ at magnitudes near 5.9. Larger apertures and steady seeing help resolve the pair cleanly.

1 Arietis — Double Star in Aries

Observable Double Star Good (52/100)

Sep: 2.9", Companion: mag 7.2

Magnitude 5.9^m DoubleStar Aries (Ari) Visible

Star Map + List + Plan Star Hop

Observe

1Physical Properties

Magnitude 5.86

Spectral Type K1III+A6V giant

Star Color Orange (B-V 0.74)

Distance 192 ly

2Position & Identifiers

RA 01h 50m 08.5s

Dec +22° 16' 31.0"

Constellation Aries (Ari)

HR 530

HIP 8544

HD 11155

Flamsteed 1 Ari

Double Cat 1457

SIMBAD

3How easy to split?

Primary 5.9 mag Companion 7.2 mag Separation 2.9″

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.	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

Set a location in User Settings to see visibility data.

Best season Sep – Nov (peak: Oct)

5Multiple Star System

Separation 2.9″

Companion Mag 7.2

Position Angle 164°

Star Colors A: Orange B: Orange

Discoverer STF 174

Notes

Binary. Component B 7.3v A6V, P.A. 166d; RV, 1.8k/s, variable. Confusion in literature as to which component is HD | 11154, which 11155. Probably combined mag. and color.

Separation over time

Measured 1782 → 2018 (236 y)

Separation drift 3.0" → 2.9" (-0.10")

Rate -0.0004" / y

PA drift 167° → 164° (-3°, -0.013°/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.