When is the best time to observe HR 2366?

HR 2366 is best observed from November through January, with peak visibility during December when it transits around midnight in the Northern Hemisphere.

Where is HR 2366 located in the sky?

HR 2366 lies in the constellation Gemini at right ascension 06h 31m and declination +16° 56′.

What telescope do I need to split HR 2366?

Splitting HR 2366 requires an aperture of roughly 80 mm or larger — the components are separated by about 7.9″ at magnitudes near 6.2. The companion is about 3.9 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

HR 2366 — Double Star in Gemini

Magnitude 6.2^m DoubleStar Gemini (Gem) Visible

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Observe

1Physical Properties

Magnitude 6.20

Spectral Type K2III giant

Star Color Red (B-V 1.16)

2Position & Identifiers

RA 06h 31m 10.1s

Dec +16° 56' 19.0"

Constellation Gemini (Gem)

HR 2366

HD 45951

SAO 95765

Double Cat 5146

3How easy to split?

Primary 6.2 mag Companion 10.1 mag Separation 7.9″

Telescope	Bortle 3	Bortle 4	Bortle 5
80 mm refractor 80mm refr.	Medium+	Medium	Hard+
150 mm Newton 150mm Newt.	Easy	Easy	Medium+
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

Set a location in User Settings to see visibility data.

Best season Nov – Jan (peak: Dec)

5Multiple Star System Triple C: optical

Components 3 (triple)

Component IDs AB

Separation 7.9″

Companion Mag 10.1

Companion Sp K0V

Position Angle 103°

Star Colors A: Red B: Orange

Discoverer STT 143

Notes

AB binary. B is K0V. Component C, 11.4v at 45" optical.

Separation over time

Measured 1843 → 2016 (173 y)

Separation drift 7.4" → 7.9" (+0.50")

Rate +0.0029" / y

PA drift 102° → 103° (+1°, +0.006°/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.