When is the best time to observe Kappa Herculis?

Kappa Herculis is best observed from April through June, with peak visibility during May when it transits around midnight in the Northern Hemisphere.

Where is Kappa Herculis located in the sky?

Kappa Herculis lies in the constellation Hercules at right ascension 16h 08m and declination +17° 03′.

What telescope do I need to split Kappa Herculis?

Splitting Kappa Herculis requires an aperture of roughly 60 mm or larger — the components are separated by about 28.1″ at magnitudes near 6.2. Larger apertures and steady seeing help resolve the pair cleanly.

Kappa Herculis — Double Star in Hercules

HIP 79045; Kappa Herculis; 7 Herculis

Magnitude 6.2^m DoubleStar Hercules (Her) Visible

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1Physical Properties

Magnitude 6.25

Spectral Type K1III giant

Star Color Orange (B-V 1.14)

Distance 1,631 ly

2Position & Identifiers

RA 16h 08m 04.9s

Dec +17° 03' 16.0"

Constellation Hercules (Her)

HR 6009

HIP 79045

HD 145000

SAO 101952

Bayer Kappa

Flamsteed 7 Her

Double Cat 9938

SIMBAD Wikipedia

3How easy to split?

Primary 6.3 mag Companion 6.2 mag Separation 28.1″

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Telescope	Bortle 3	Bortle 4	Bortle 5
80 mm refractor 80mm refr.	Easy	Easy	Easy
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

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Best season Apr – Jun (peak: May)

5Multiple Star System Triple

Components 3 (triple)

Component IDs AB

Separation 28.1″

Companion Mag 6.2

Position Angle 14°

Star Colors A: Orange B: Orange

Notes

Optical pair with HR 6008.

Eyepiece View

Telescope Eyepiece

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80x Dawes: 1.9″ TFOV: 0.6°

Seeing

Scale Realistic = true angular size

A: 6.2 · B: 6.2 · Sep: 28.1″ · PA: 14° · N up, E right

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

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6

Size Comparison

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7

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8

Spectral Classification

9

Hertzsprung-Russell Diagram

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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

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14Stellar Notes

Spectral

Also classified K0IV, K2II and K2III.

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.

Marsic

Kappa Her (BS6008)

Easy

Easy double, sep 27.1″

Double Star mag 5.00 0.0° Hercules

NGC 6027

Hard+

Bright spiral galaxy

Galaxy mag 12.4 4.3° Serpens

Blaze Star

HR 5958

Medium+

Mira-type variable, range 2.0–10.8

Variable Star mag 10.00 9.1° Corona Borealis

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