47 Tucanae (NGC 104)
The second brightest globular cluster in the sky, visible to the naked eye near the Small Magellanic Cloud.
Globular cluster in Tucana. Magnitude 4.0.
Can you see it from Guyana?
From Georgetown (6.8° N) it climbs to 11° above the southern horizon at its highest; from Lethem (3.4° N), to 15° above the southern horizon. It is highest at midnight on the night of 24 Sep, 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 from a dark site as a fuzzy star next to the Small Magellanic Cloud, low in the south: 11° from Georgetown, 15° from Lethem.
- 10x50 binoculars: A round glow, brighter towards the middle.
- A small telescope (80 to 100 mm): One of the two finest globulars: a small telescope resolves many stars around a bright core.
- A camera: Spans about 40% of an APS-C frame at 1,000 mm (field 1.3° × 0.9°); needs a tracking mount.
How big, how bright, how far
- Size on the sky: 31′, 100% of the Moon's width (the Moon is about 31′ wide).
- Brightness: magnitude 4.0. Brighter than the faintest stars Georgetown shows (4.3), and Lethem's (6.0).
- Distance: 13,000 light-years. The light reaching your eye left it about 13,000 years ago.
What it is made of
- Type
- Globular Cluster
- Distance
- Approx. 13,000 Lightyears
- True size
- Approx. 120 Lightyears diameter
- Old Stars (Hundreds of Thousands to Millions): Second brightest globular cluster, very dense core
- Blue Stragglers: Unusually hot, blue stars in the core
- Minimal Gas and Dust: Little material for new star formation
More deep-sky objects: NGC 2516 (Southern Beehive / Diamond Cluster) · Southern Pleiades (IC 2602) · Jewel Box Cluster (NGC 4755) · Wishing Well Cluster (NGC 3532) · IC 2391 (Omicron Velorum Cluster) · M55 (Globular Cluster)