Stars · Red supergiant

UY Scuti

5,900 light-years · Light crosses it in 70 minutes

Across

1.3 billion km

Vs Earth

909× Sun

Mass

7 Suns

Open UY Scuti in Cosmic Scale

About

UY Scuti is a pulsating red supergiant in the constellation Scutum, and for years it topped the lists of the largest known stars. Later distance measurements make it less certain, which is typical of these enormous, poorly-defined stars.

Once listed as the largest known star.

At a glance

Distance	About 5,900 light-years
Surface	3,365 K
Radius	Around 900 Suns
Variability	Pulsates over ~740 days

Did you know

1. Its edge is not sharp: the star fades gradually into its own wind, so its 'size' depends on where you stop measuring.
2. Placed where the Sun is, its surface would reach past the asteroid belt.
3. It loses about the mass of Earth every few years to its stellar wind.