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HIP 105312 — Double Star in Capricornus

Magnitude 6.6m DoubleStar Capricornus (Cap) Visible
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1Physical Properties

Magnitude 6.56
Spectral Type G5V
Star Color Orange (B-V 0.73)
Distance 58 ly

2Position & Identifiers

RA 21h 19m 45.8s
Dec -26° 21' 11.0"
Constellation Capricornus (Cap)
HR 8148
HIP 105312
HD 202940
SAO 190236
Double Cat 14847
SIMBAD

3How easy to split?

Primary 6.6 mag Companion 9.8 mag Separation 0.8″
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Telescope Bortle 3 Bortle 4 Bortle 5
80mm refr. V. hard V. hard V. hard
150mm Newt. V. hard V. hard V. hard
C8 203mm V. hard+ V. hard+ V. hard+
Easy Medium Hard Very hard Impossible

Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs

To reach "Medium" at Bortle 3, you'd need at least a 480 mm reflector.

4Visibility

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Best season Jul – Sep (peak: Aug)

5Multiple Star System Quintuple C,D,E: optical

Components 5 (quintuple)
Component IDs AB
Separation 0.8″
Companion Mag 9.8
Companion Sp K4
Position Angle 36°
Star Colors A: Orange B: Red
Discoverer BU 271
AB binary. B is K4. Components D and E, 12v at 247" and 149" probably optical.

Separation over time

Period: 183.3 y Eccentricity: 0.660 Now: 0.75", PA 51° -0.11" in 5 years
0.00" 0.32" 0.64" 0.96" 1.3" 2025 2030 2035 2040 2045 0.75"

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

Eyepiece View

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80x Dawes: 1.9″ TFOV: 0.6°
Realistic = true angular size
N E 36°

A: 6.6 · B: 9.8 · Sep: 0.8″ · PA: 36° · N up, E right

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

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6

Size Comparison

Querying VizieR for stellar data…
7

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8

Spectral Classification

9

Hertzsprung-Russell Diagram

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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

ADS 14847A, 21.3462d, K 24.0k/s, V0 -17.2k/s, asini 6.82.
0.049".
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.

24 Cap
Hard+
Cool red giant
Double Star mag 4.50 3.1° Capricornus
IC 5086
Hard+
Elliptical galaxy
Galaxy mag 12.84 4.2° Microscopium
M30
Jellyfish Cluster
Easy
Globular cluster — dense ball of ancient stars
Globular Cluster mag 7.2 5.7° Capricornus
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