M56 (Globular Cluster)
A globular cluster in Lyra, 8° from the plane of the Milky Way, so it sits in a busy field of stars. Its stars are poor in heavy elements: only 14 of the 152 globulars with a measured metallicity are poorer.
Globular cluster in Lyra. Magnitude 8.2.
Can you see it from Guyana?
From Georgetown (6.8° N) it climbs to 67° above the northern horizon at its highest; from Lethem (3.4° N), to 63° above the northern horizon. It is highest at midnight on the night of 9 Jul, 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 3.8° north-west of Albireo.
- 10x50 binoculars: A round glow, brighter towards the middle.
- A small telescope (80 to 100 mm): A small round glow; at 100x and above its edge turns grainy against the busy Milky Way field.
- 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: 5.8′, 19% of the Moon's width (the Moon is about 31′ wide).
- Brightness: magnitude 8.2. Fainter than the faintest stars in Georgetown (4.3) and Lethem (6.0): binoculars or a telescope.
- Distance: 34,000 light-years. The light reaching your eye left it about 34,000 years ago.
- True size: 57 light-years across its catalogued outline; light crosses it in 57 years.
Apparent size from OpenNGC (Mattia Verga), CC-BY-SA-4.0.
What it is made of
- Type
- Globular cluster
- Mass
- About 166,000 times the Sun's mass
- Notable
- Metal-poor: [Fe/H] -1.98, poorer than 138 of the 152 globulars measured.
Measured: Which generation its red giants belong to (420 measured near its centre).
- Second generation: 53.1%, born from gas the first stars enriched
- First generation: 46.9%, ± 4.1%
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: 46.9% ± 4.1% first generation among 420 red giants (NGC 6779; 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 6779: 10.43 +/- 0.14 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 6779: 166,000 ± 7,570 Suns), retrieved 2026-10-21; Baumgardt & Vasiliev 2021, MNRAS 505, 5957.
More deep-sky objects: M71 (Globular Cluster) · M29 (Open Cluster) · IC 4756 (Open Cluster) · NGC 6633 (Open Cluster) · M92 (Globular Cluster) · M39 (Open Cluster)