Arcturus compared to the Sun

Orange giant star on a steep, tilted orbit through the galaxy, unlike most nearby stars.

How big is Arcturus compared to the Sun?

Arcturus is roughly 25 times as wide as the Sun.

Arcturus has about the same mass as the Sun.

Arcturus’s surface is 4,013 °C. The Sun’s surface is 5,499 °C.

You see Arcturus as it was 36.7 years ago.

How much light it gives off: 170 solar luminosities.
What it is: An orange giant star, puffed up to about 25 times the Sun’s width — and an old one, on an orbit unlike the Sun’s.; How we know: Its measured speed and direction don’t match the smooth rotation of the galactic disc: it is an old star of the galaxy’s thick disc, once thought to be a halo star. Rung 5 of the cosmic ladder — the distance to nearby stars
Its name and its story: Greek for “Guardian of the Bear”. Its light ceremonially lit the 1933 Chicago World’s Fair, based on a (slightly incorrect) estimate that its light left 40 years earlier.

The numbers