When is the best time to observe HIP 23916?

HIP 23916 is best observed from November through January, with peak visibility during December when it transits around midnight in the Northern Hemisphere.

Where is HIP 23916 located in the sky?

HIP 23916 lies in the constellation Eridanus at right ascension 05h 08m and declination -08° 40′.

What telescope do I need to split HIP 23916?

Splitting HIP 23916 requires an aperture of roughly 60 mm or larger — the components are separated by about 21.3″ at magnitudes near 5.8. The companion is about 3.2 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

HIP 23916 — Double Star in Eridanus

Observable Double Star Good (57/100)

Sep: 21.3", Companion: mag 9.0

Magnitude 5.8^m DoubleStar Eridanus (Eri) Visible

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Observe

1Physical Properties

Magnitude 5.78

Spectral Type B8V

Star Color Blue-white (B-V -0.06)

2Position & Identifiers

RA 05h 08m 20.2s

Dec -08° 39' 54.0"

Constellation Eridanus (Eri)

HR 1671

HIP 23916

HD 33224

SAO 131806

Double Cat 3722

SIMBAD

3How easy to split?

Primary 5.8 mag Companion 9.0 mag Separation 21.3″

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Telescope	Bortle 3	Bortle 4	Bortle 5
80 mm refractor 80mm refr.	Easy	Medium+	Medium+
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 Nov – Jan (peak: Dec)

5Multiple Star System Triple C: optical

Components 3 (triple)

Component IDs AB

Separation 21.3″

Companion Mag 9.0

Position Angle 69°

Star Colors A: Blue-white B: Yellow

Discoverer STF 649

Notes

ADS 3722B, K0III-IV, RV +72k/s.

Separation over time

Measured 1821 → 2017 (196 y)

Separation drift 21.8" → 21.3" (-0.50")

Rate -0.0026" / y

PA drift 80° → 69° (-11°, -0.056°/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.