Pleiades

cluster

The Pleiades (M45) — the brightest and one of the nearest open star clusters, ~444 light-years away in the Orion Arm: a few hundred hot blue stars, the brightest wrapped in a blue reflection nebula of dust they are drifting through. A naked-eye landmark on every continent for millennia.

Open in 3D viewSee Pleiades in the live, interactive 3D map

Science

Physical

Type: Open star cluster + blue reflection nebula
Distance: ~444 light-years
Members: Several hundred stars; ~1,000 gravitationally bound
Age: ~100 million years (young, hot blue stars)

How we know

Note: The image is a REAL photograph (NASA/Palomar Observatory, AURA/Caltech), shown as a camera-facing billboard at the cluster's real position — presented as seen from Earth.

Discovery & history

Name: Messier's 45th entry; the Greek Pleiades, seven mythic sisters. Japanese 'Subaru'.

Known to every ancient culture (the 'Seven Sisters'); Galileo first resolved dozens of its stars by telescope in 1610. Hubble later refined its distance.

Images

The Pleiades (M45) — a real photograph of the Seven Sisters, blue stars wrapped in reflection nebulosity. — NASA, ESA, AURA/Caltech, Palomar Observatory — public domain · Wikimedia Commons

Images from open archives · credit shown per image