When is the best time to observe HIP 30840?

HIP 30840 is best observed from November through January, with peak visibility during December when it transits around midnight in the Northern Hemisphere.

Where is HIP 30840 located in the sky?

HIP 30840 lies in the constellation Canis Major at right ascension 06h 29m and declination -32° 22′.

What telescope do I need to split HIP 30840?

Splitting HIP 30840 requires an aperture of roughly 150 mm or larger — the components are separated by about 1.2″ at magnitudes near 5.7. Larger apertures and steady seeing help resolve the pair cleanly.

HIP 30840 — Double Star in Canis Major

Observable Double Star Fair (24/100)

Sep: 1.2", Companion: mag 7.6

Magnitude 5.7^m DoubleStar Canis Major (CMa) Visible

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Observe

1Physical Properties

Magnitude 5.74

Spectral Type B4Vnpe

Star Color Blue (B-V -0.17)

Distance 544 ly

2Position & Identifiers

RA 06h 28m 39.2s

Dec -32° 22' 16.0"

Constellation Canis Major (CMa)

HR 2364

HIP 30840

HD 45871

SAO 196861

Variable ID Var

SIMBAD

3How easy to split?

Primary 5.7 mag Companion 7.6 mag Separation 1.2″

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

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

Separation 1.2″

Companion Mag 7.6

Position Angle 42°

Star Colors A: Blue B: White

Discoverer BU 753

Separation over time

Measured 1879 → 2016 (137 y)

Separation drift 1.2" → 1.2" (+0.00")

Rate +0.0000" / y

PA drift 40° → 42° (+2°, +0.015°/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.