When is the best time to observe V451 Herculis?

V451 Herculis is best observed from May through July, with peak visibility during June when it transits around midnight in the Northern Hemisphere.

Where is V451 Herculis located in the sky?

V451 Herculis lies in the constellation Hercules at right ascension 17h 02m and declination +14° 57′.

What telescope do I need to split V451 Herculis?

Splitting V451 Herculis requires an aperture of roughly 60 mm or larger — the components are separated by about 18.7″ at magnitudes near 6.3. The companion is about 4.0 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

V451 Herculis — Double Star in Hercules

Magnitude 6.3^m DoubleStar Hercules (Her) Visible

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Observe

1Physical Properties

Magnitude 6.31

Range 6.26 - 6.34

Period 6.0 days

Variable Type Alpha2 CVn (Magnetic Rotating)

Spectral Type B9pCrEu

Star Color Blue-white (B-V 0.04)

2Position & Identifiers

RA 17h 01m 33.0s

Dec +14° 56' 58.0"

Constellation Hercules (Her)

HR 6326

HIP 83308

HD 153882

SAO 102536

Variable ID V451 Her

Double Cat 10310

SIMBAD

3How easy to split?

Primary 6.3 mag Companion 10.3 mag Separation 18.7″

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Telescope	Bortle 3	Bortle 4	Bortle 5
80 mm refractor 80mm refr.	Medium	Medium	Hard+
150 mm Newton 150mm Newt.	Easy	Medium+	Medium+
Celestron C8 (203 mm SCT) C8 203mm	Easy	Easy	Medium+

Easy Medium Hard Very hard Impossible

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

4Visibility

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Best season May – Jul (peak: Jun)

5Light Curve

6Multiple Star System

Separation 18.7″

Companion Mag 10.3

Position Angle 238°

Star Colors A: Blue-white B: Yellow

Discoverer H 4 122

Notes

Fixed sep.

Separation over time

Measured 1783 → 2023 (240 y)

Separation drift 21.1" → 18.7" (-2.40")

Rate -0.0100" / y

PA drift 245° → 238° (-7°, -0.029°/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.