Menu

10 Arietis — Double Star in Aries

Observable Double Star Fair (21/100)

Sep: 1.6", Companion: mag 7.9

Magnitude 5.6m DoubleStar Aries (Ari) Visible
Star Map
+ List + Plan Star Hop

Observe

1Physical Properties

Magnitude 5.63
Spectral Type F8IV subgiant
Star Color Yellow (B-V 0.54)
Distance 130 ly

2Position & Identifiers

RA 02h 03m 39.3s
Dec +25° 56' 08.0"
Constellation Aries (Ari)
HR 605
HIP 9621
HD 12558
SAO 75114
Flamsteed 10 Ari
Double Cat 1631
SIMBAD

3How easy to split?

Primary 5.6 mag Companion 7.9 mag Separation 1.7″
Sign in and configure your equipment and default location to see a personalized row.
Telescope Bortle 3 Bortle 4 Bortle 5
80mm refr. Hard Hard Hard
150mm Newt. Medium Medium Medium
C8 203mm Medium+ Medium+ Medium+
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 Triple

Components 3 (triple)
Component IDs AB
Separation 1.6″
Companion Mag 7.9
Position Angle 347°
Star Colors A: Yellow B: Orange
Discoverer STF 208
AB 5.90 F8IV, 7.27 F9V, 288.0y, a = 1.256"; or 309.03y, a = 1.34". Other published periods have ranged from 247 to | 925y. Combined mag., colors.

Separation over time

Period: 325.0 y Eccentricity: 0.590 Now: 1.7", PA 352° + 0.06" in 5 years
0.00" 0.54" 1.1" 1.6" 2.2" 2025 2030 2035 2040 2045 1.7"

Apparent separation over time, computed from ORB6 orbital elements. Steep curves indicate fast-changing pairs — catch them while they're splittable.

Eyepiece View

Log in to set your own equipment
80x Dawes: 1.9″ TFOV: 0.6°
Realistic = true angular size
N E 347°

A: 5.6 · B: 7.9 · Sep: 1.6″ · PA: 347° · N up, E right

Unresolved · Rayleigh: 2.3″ · Dawes: 1.9″ · Eff: 2.3″

Explore

6

Size Comparison

Querying VizieR for stellar data…
7

Compare Stars

8

Spectral Classification

9

Hertzsprung-Russell Diagram

Loading HR diagram…
Read: The Hertzsprung-Russell Diagram — Reading Stars Like a Map
10

Stellar Lifecycle

11

Blackbody Spectrum

12

Stellar Absorption Spectrum

Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.

13

Stellar Fusion

Discover

14Stellar Notes

0.016".
15

Light Travel Time Machine

16

Relativistic Travel

Nearby in the Sky

Other targets within a few degrees — pan your scope a little and keep exploring.

Visibility scores assume a 150 mm Newton at Bortle 4.

14 Ari
Easy
Easy double, sep 106.2″
Double Star mag 4.98 1.3° Aries
Lambda Ari
Easy
Easy double, sep 37.3″
Double Star mag 4.79 2.7° Aries
NGC 855
Hard+
Elliptical galaxy
Galaxy mag 13.0 3.0° Triangulum
6 Tri
Easy
Easy double, sep 3.9″
Double Star mag 4.94 4.8° Triangulum
Show on Map

Explore Nightbase

Related knowledge, tools, and stories — no observation planning required.

Double Stars — A Guide for Observers
Two suns where one appeared — how to find, split, and appreciate the night sky's finest pairs. From Albireo's gold-and-blue to the Sirius B challenge.
Article
Aries
Mythology, bright stars, and deep-sky highlights.
Constellation
Jupiter
The Great Red Spot, cloud belts, and the Galilean moons.
Deep dive
}