M73 (Asterism)
A small group of stars in Aquarius that Messier took for a cluster. Gaia shows its three brightest stars are unrelated: about 1,030, 1,250 and 2,290 light-years away.
Asterism in Aquarius. Magnitude 8.9.
Can you see it from Guyana?
From Georgetown (6.8° N) it climbs to 71° above the southern horizon at its highest; from Lethem (3.4° N), to 74° above the southern horizon. It is highest at midnight on the night of 3 Aug, 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 10.7° south-west of Sadalsuud.
- 10x50 binoculars: Not separated in binoculars: a faint point of light.
- A small telescope (80 to 100 mm): Three or four stars close together at medium power; M72 is 1.3° to the west.
- A camera: A few stars on any long-focus frame; nothing more to bring out.
How big, how bright, how far
- Brightness: magnitude 8.9. Fainter than the faintest stars in Georgetown (4.3) and Lethem (6.0): binoculars or a telescope.
- Distance: Between about 1,000 and 2,300 light-years. The light reaching your eye left it between about 1,000 and 2,300 years ago.
What it is made of
- Type
- Asterism (a chance line-up of stars)
- Notable
- A chance line-up: Gaia DR3 puts its three brightest stars at about 1,030, 1,250 and 2,290 light-years.
What is in it, not measured:
- Unrelated stars: that only line up from where we stand
How we know: Distance from the Gaia parallax of each of its three brightest stars: Gaia DR3 (VizieR I/355/gaiadr3), distance = 1/parallax, retrieved 2026-10-21: Gaia DR3 6888761925104124544 (G 10.00) 1.424 ± 0.0151 mas; Gaia DR3 6888762676722911104 (G 11.48) 3.1658 ± 0.0274 mas; Gaia DR3 6888763058975491840 (G 11.13) 2.6105 ± 0.0199 mas. True size: Not one object (stars at different distances), a chance line-up of unrelated stars, not one object; Gaia DR3 parallaxes, see distance.
More deep-sky objects: Brocchi's Cluster (Coathanger) · M40 (Double Star) · M72 (Globular Cluster) · Saturn Nebula (NGC 7009) · M30 (Globular Cluster) · M2 (Globular Cluster)