IC 2391 (Omicron Velorum Cluster)
A bright open cluster in Vela surrounding the star Omicron Velorum, easily visible to the naked eye and a fine sight in binoculars.
Open cluster in Vela. Magnitude 2.5.
Can you see it from Guyana?
From Georgetown (6.8° N) it climbs to 30° above the southern horizon at its highest; from Lethem (3.4° N), to 34° above the southern horizon. It is highest at midnight on the night of 28 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: Visible to the eye only from a dark site, as a hazy knot of stars; lost in city skies.
- 10x50 binoculars: Resolves into dozens of stars.
- A small telescope (80 to 100 mm): Dozens to hundreds of stars at low power.
- A camera: Spans about 40% of an APS-C frame at 600 mm (field 2.2° × 1.5°); needs a tracking mount.
How big, how bright, how far
- Size on the sky: 50′, 1.6 Moons across (the Moon is about 31′ wide).
- Brightness: magnitude 2.5. Brighter than the faintest stars Georgetown shows (4.3), and Lethem's (6.0).
- Distance: 490 light-years. The light reaching your eye left it about 490 years ago, around the year 1540.
What it is made of
- Type
- Open cluster
- Distance
- Approx. 490 Lightyears
- True size
- Approx. 7.1 Lightyears across
- Age
- about 27 million years (range 14 million years to 48 million years)
- Notable
- One of the nearest star clusters: only 93 of the 7,168 clusters in the Gaia DR3 catalogue are closer.
More deep-sky objects: NGC 2516 (Southern Beehive / Diamond Cluster) · Southern Pleiades (IC 2602) · Wishing Well Cluster (NGC 3532) · M93 (Open Cluster) · Jewel Box Cluster (NGC 4755) · M41 (Open Cluster)