R Coronae Australis Nebula (NGC 6729)
A small fan of dust in Corona Australis lit by R Coronae Australis, a variable star. At about 410 light-years it is the nearest nebula on this site.
Nebula in Corona Australis.
Can you see it from Guyana?
From Georgetown (6.8° N) it climbs to 46° above the southern horizon at its highest; from Lethem (3.4° N), to 50° above the southern horizon. It is highest at midnight on the night of 5 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 7.1° south of Ascella.
- 10x50 binoculars: Not visible in binoculars.
- A small telescope (80 to 100 mm): A small, faint fan of light from the star R CrA at its tip; a dark site helps.
- A camera: Spans about 40% of an APS-C frame at 1,500 mm (field 0.9° × 0.6°); needs a tracking mount.
How big, how bright, how far
- Size on the sky: 25′ × 20′, 80% of the Moon's width (the Moon is about 31′ wide).
- Distance: 410 light-years. The light reaching your eye left it about 410 years ago, around the year 1620.
- True size: 3 light-years across its catalogued outline; light crosses it in 3 years.
Apparent size from OpenNGC (Mattia Verga), CC-BY-SA-4.0.
What it is made of
- Type
- Reflection nebula
- Notable
- The nearest nebula on this site: about 410 light-years, by the Gaia parallax of R Coronae Australis.
What is in it, not measured:
- Dust: scattering a nearby star's light, which is why it looks blue
- Cold gas: that the dust lives in
- A young star: that lights it
How we know: Distance from the Gaia parallax of R Coronae Australis, the young star that lights it: Gaia EDR3 parallax via SIMBAD (basic.plx_value, 2020yCat.1350....0G), distance = 1/parallax, retrieved 2026-10-21 (R CrA: 7.9872 +/- 0.4874 mas). True size: the apparent size times the distance (apparent size: OpenNGC (Mattia Verga, CC BY-SA 4.0), commit 4e2398a2).
More deep-sky objects: Lagoon Nebula (M8) · Trifid Nebula (M20) · Omega Nebula (M17) · IC 4628 (Nebula) · Rho Ophiuchi Nebula (IC 4604) · Tarantula Nebula (NGC 2070)