Caroline's Cluster (NGC 2360)
A rich open cluster in Canis Major, 7.9° east of Sirius. At about 1.5 billion years it is old for an open cluster, and Gaia counts nearly 1,200 member stars.
Open cluster in Canis Major. Magnitude 7.2.
Can you see it from Guyana?
From Georgetown (6.8° N) it climbs to 68° above the southern horizon at its highest; from Lethem (3.4° N), to 71° above the southern horizon. It is highest at midnight on the night of 7 Jan, in the middle of its season. The page works out tonight's rise, highest point and set for both towns in Guyana time (UTC-4), and where the Moon is.
What you'll see
- Your eyes: Not visible to the eye. It lies 7.9° east of Sirius.
- 10x50 binoculars: A small hazy knot with a few stars resolved.
- A small telescope (80 to 100 mm): A rich, even scatter of faint stars at low power; it looks like a sprinkle of sugar.
- A camera: Tiny on camera: it needs 2,000 mm or more of focal length on a tracking mount.
How big, how bright, how far
- Size on the sky: 9′, 29% of the Moon's width (the Moon is about 31′ wide).
- Brightness: magnitude 7.2. Fainter than the faintest stars in Georgetown (4.3) and Lethem (6.0): binoculars or a telescope.
- Distance: 3,400 light-years. The light reaching your eye left it about 3,400 years ago.
- True size: 8.9 light-years across its catalogued outline; light crosses it in 8.9 years.
Apparent size from OpenNGC (Mattia Verga), CC-BY-SA-4.0.
What it is made of
- Type
- Open cluster
- Mass
- About 2,800 times the Sun's mass, in its stars
- Age
- About 1.5 billion years (range 960 million years to 2.2 billion years)
What is in it, not measured:
- Stars born together: from one cloud of gas, at one time
- Red giants: stars that have already aged and swollen
How we know: Distance from Gaia parallaxes of its stars: Hunt & Reffert 2024, A&A 686, A42 (Gaia DR3 cluster catalogue, VizieR J/A+A/686/A42), retrieved 2026-10-21: NGC 2360 1,042 pc; statistical 3,394-3,401 ly (16th-84th percentile); Gaia DR3 parallax zero-point systematics (about 0.02 mas) add about 2%. True size: the apparent size times the distance (apparent size: OpenNGC (Mattia Verga, CC BY-SA 4.0), commit 4e2398a2). Mass: Hunt & Reffert 2024, A&A 686, A42 (Gaia DR3 cluster catalogue, VizieR J/A+A/686/A42), retrieved 2026-10-21, NGC 2360: total 2,780 ± 104 Suns.
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More deep-sky objects: M47 (Open Cluster) · M46 (Open Cluster) & NGC 2438 (Planetary Nebula) · M50 (Open Cluster) · M41 (Open Cluster) · NGC 2362 (Open Cluster) · M93 (Open Cluster)