M9 (Globular Cluster)
A globular cluster in Ophiuchus, 3.5° from Sabik, in the direction of the centre of the Milky Way. Hubble resolves its stars right into the core, and shows them in different colours.
Globular cluster in Ophiuchus. Magnitude 7.7.
Can you see it from Guyana?
From Georgetown (6.8° N) it climbs to 65° above the southern horizon at its highest; from Lethem (3.4° N), to 68° above the southern horizon. It is highest at midnight on the night of 9 Jun, 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 3.5° south-east of Sabik.
- 10x50 binoculars: A round glow, brighter towards the middle.
- A small telescope (80 to 100 mm): A small, fairly bright glow with a brighter middle; it starts to resolve only at high power.
- 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: 6.9′, 22% of the Moon's width (the Moon is about 31′ wide).
- Brightness: magnitude 7.7. Fainter than the faintest stars in Georgetown (4.3) and Lethem (6.0): binoculars or a telescope.
- Distance: 27,100 light-years. The light reaching your eye left it about 27,100 years ago.
- True size: 54 light-years across its catalogued outline; light crosses it in 54 years.
Apparent size from OpenNGC (Mattia Verga), CC-BY-SA-4.0.
What it is made of
- Type
- Globular cluster
- Mass
- About 310,000 times the Sun's mass
- Notable
- Hubble resolves its stars right into the centre and shows their different colours: redder stars are cooler, blue ones extremely hot.
What is in it, not measured:
- Old stars: among the oldest in the Milky Way
- Stellar remnants: white dwarfs and neutron stars
- Almost no gas or dust
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 6333: 8.3 +/- 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 6333: 308,000 ± 23,200 Suns), retrieved 2026-10-21; Baumgardt & Vasiliev 2021, MNRAS 505, 5957.
More deep-sky objects: M19 (Globular Cluster) · M23 (Open Cluster) · M21 (Open Cluster) · M62 (Globular Cluster) · M107 (Globular Cluster) · M18 (Open Cluster)