War and Peace Nebula (NGC 6357)
A large glowing cloud in Scorpius, 3.3° north of Lesath, lit by the young cluster inside it. It shares one complex of gas with the Cat's Paw Nebula, 2.1° away, both about 5,500 light-years off.
Nebula and star cluster in Scorpius.
Can you see it from Guyana?
From Georgetown (6.8° N) it climbs to 49° above the southern horizon at its highest; from Lethem (3.4° N), to 52° above the southern horizon. It is highest at midnight on the night of 10 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 3.3° north of Lesath.
- 10x50 binoculars: Hard: a faint glow from a dark site with a nebula filter.
- A small telescope (80 to 100 mm): Large and faint: low power and a UHC or OIII filter show the glow round its young cluster.
- A camera: Spans about 40% of an APS-C frame at 400 mm (field 3.4° × 2.2°); needs a tracking mount. An H-alpha-sensitive (modified) camera brings out its red glow. The photo above is a near-infrared VISTA view.
How big, how bright, how far
- Size on the sky: 90′, 2.9 Moons across (the Moon is about 31′ wide).
- Distance: 5,500 light-years. The light reaching your eye left it about 5,500 years ago.
- True size: 140 light-years across its catalogued outline; light crosses it in 140 years.
What it is made of
- Type
- Emission nebula with a young cluster
- Mass
- About 2,300 times the Sun's mass, in the stars of its cluster NGC 6357
- Age
- About 17 million years (range 5.1 million years to 33 million years), the age of NGC 6357
What is in it, not measured:
- Ionised hydrogen: glows red where hot stars light it
- Helium and heavier gases: with traces of oxygen, nitrogen and sulphur
- Dust: in dark lanes
- Young hot stars: that light it
How we know: Distance from Gaia parallaxes of the stars of NGC 6357, the cluster inside it: Hunt & Reffert 2024, A&A 686, A42 (Gaia DR3 cluster catalogue, VizieR J/A+A/686/A42), retrieved 2026-10-21: NGC 6357 1,672 pc; statistical 5,432-5,476 ly (16th-84th percentile); Gaia DR3 parallax zero-point systematics (about 0.02 mas) add about 3%. True size: the apparent size times the distance (apparent size: Sharpless 1959, ApJS 4, 257 (VizieR VII/20), Sh2-11). Mass: Hunt & Reffert 2024, A&A 686, A42 (Gaia DR3 cluster catalogue, VizieR J/A+A/686/A42), retrieved 2026-10-21, NGC 6357: total 2,321 ± 517 Suns.
More deep-sky objects: Butterfly Cluster (M6) · NGC 6281 (Open Cluster) · Ptolemy Cluster (M7) · M62 (Globular Cluster) · M19 (Globular Cluster) · NGC 6231 (Northern Jewel Box)