M80 (Globular Cluster)
A compact globular cluster in Scorpius, 2.8° from Alniyat and north-west of Antares. It packs about 321,000 Suns into a ball whose brighter half is only about 13 light-years across.
Globular cluster in Scorpius. Magnitude 7.4.
Can you see it from Guyana?
From Georgetown (6.8° N) it climbs to 60° above the southern horizon at its highest; from Lethem (3.4° N), to 64° above the southern horizon. It is highest at midnight on the night of 24 May, 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 2.8° north of Alniyat.
- 10x50 binoculars: A round glow, brighter towards the middle.
- A small telescope (80 to 100 mm): A small, very concentrated ball that looks like a fuzzy star at low power; it resists resolving.
- 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: 5.7′, 18% of the Moon's width (the Moon is about 31′ wide).
- Brightness: magnitude 7.4. Fainter than the faintest stars in Georgetown (4.3) and Lethem (6.0): binoculars or a telescope.
- Distance: 33,700 light-years. The light reaching your eye left it about 33,700 years ago.
- True size: 56 light-years across its catalogued outline; light crosses it in 56 years.
Apparent size from OpenNGC (Mattia Verga), CC-BY-SA-4.0.
What it is made of
- Type
- Globular cluster
- Mass
- About 321,000 times the Sun's mass
Measured: Which generation its red giants belong to (668 measured near its centre).
- Second generation: 64.9%, born from gas the first stars enriched
- First generation: 35.1%, ± 2.9%
Gas: searches of globular clusters mostly find only upper limits (Pancino et al. 2024, arXiv:2404.05548). Hubble ultraviolet colours split its red giants into a first generation and later, chemically enriched ones: 35.1% ± 2.9% first generation among 668 red giants (NGC 6093; Milone et al. 2017, MNRAS 464, 3636, Table 2).
Also in it, not measured:
- Stellar remnants: white dwarfs and neutron stars
- Almost no gas or dust: not in this tally
How we know: Distance from Gaia, Hubble and earlier distances to its stars, combined: Baumgardt & Vasiliev 2021, MNRAS 505, 5957; Baumgardt globular cluster database, combined_table.txt, retrieved 2026-10-21 (NGC 6093: 10.34 +/- 0.12 kpc). True size: the apparent size times the distance (apparent size: OpenNGC (Mattia Verga, CC BY-SA 4.0), commit 4e2398a2). Mass: Baumgardt globular cluster database, combined_table.txt (NGC 6093: 321,000 ± 8,920 Suns), retrieved 2026-10-21; Baumgardt & Vasiliev 2021, MNRAS 505, 5957.
More deep-sky objects: Globular Cluster M4 · M107 (Globular Cluster) · M19 (Globular Cluster) · M62 (Globular Cluster) · M9 (Globular Cluster) · NGC 6124 (Open Cluster)