When is the best time to observe Kappa Bootis?

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

Where is Kappa Bootis located in the sky?

Kappa Bootis lies in the constellation Boötes at right ascension 14h 13m and declination +51° 47′.

What telescope do I need to split Kappa Bootis?

Splitting Kappa Bootis requires an aperture of roughly 60 mm or larger — the components are separated by about 13.7″ at magnitudes near 4.5. Larger apertures and steady seeing help resolve the pair cleanly.

Kappa Bootis — Double Star in Boötes

HIP 69483; Kappa2 Bootis; 17 Bootis

Observable Double Star Good (58/100)

Sep: 13.7", Companion: mag 6.6

Magnitude 4.5^m DoubleStar Boötes (Boo) Visible

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Observe

1Physical Properties

Magnitude 4.54

Range 4.5 - 4.58

Period 1.8 hours

Variable Type Delta Scuti (Low Amplitude)

Spectral Type A8IV subgiant

Star Color Yellow-white (B-V 0.20)

Distance 326 ly

2Position & Identifiers

RA 14h 13m 29.0s

Dec +51° 47' 25.0"

Constellation Boötes (Boo)

HR 5329

HIP 69483

HD 124675

SAO 29046

Bayer Kappa2

Flamsteed 17 Boo

Variable ID Kap2 Boo

Double Cat 9173

SIMBAD Wikipedia

3How easy to split?

Primary 4.5 mag Companion 6.6 mag Separation 13.7″

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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 Mar – May (peak: Apr)

5Light Curve

6Multiple Star System

Separation 13.7″

Companion Mag 6.6

Companion Sp F1V

Position Angle 236°

Star Colors A: Yellow-white B: Yellow-white

Discoverer STF1821

Notes

Binary with HR 5328.

Separation over time

Measured 1779 → 2023 (244 y)

Separation drift 12.5" → 13.7" (+1.20")

Rate +0.0049" / y

PA drift 240° → 236° (-4°, -0.016°/y)

Slow change over generations — observable in lifetime comparisons.

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.