When is the best time to observe 37 Herculis?

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

Where is 37 Herculis located in the sky?

37 Herculis lies in the constellation Hercules at right ascension 16h 41m and declination +04° 13′.

What telescope do I need to split 37 Herculis?

Splitting 37 Herculis requires an aperture of roughly 60 mm or larger — the components are separated by about 69.3″ at magnitudes near 5.8. Larger apertures and steady seeing help resolve the pair cleanly.

37 Herculis — Double Star in Hercules

Observable Double Star Good (55/100)

Sep: 69.3", Companion: mag 6.9

Magnitude 5.8^m DoubleStar Hercules (Her) Visible

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Observe

1Physical Properties

Magnitude 5.77

Spectral Type A1V

Star Color White (B-V -0.02)

Distance 3,262 ly

2Position & Identifiers

RA 16h 40m 38.7s

Dec +04° 13' 11.0"

Constellation Hercules (Her)

HR 6195

HIP 81641

HD 150378

SAO 121776

Flamsteed 37 Her

Double Cat 10149

SIMBAD

3How easy to split?

Primary 5.8 mag Companion 6.9 mag Separation 69.3″

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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 Quadruple

Components 4 (quadruple)

Component IDs AB

Separation 69.3″

Companion Mag 6.9

Companion Sp A3IV

Position Angle 229°

Star Colors A: White B: White

Discoverer STFA 31

Notes

Binary with HR 6194, q.v.

Separation over time

Measured 1777 → 2017 (240 y)

Separation drift 69.0" → 69.3" (+0.30")

Rate +0.0012" / y

PA drift 228° → 229° (+1°, +0.004°/y)

Essentially fixed on human timescales — the same view your grandchildren will see.

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.