Alioth is the brightest star of Ursa Major, the first star of the Plough’s handle, a white star whose brightness shifts slightly as it spins.
At a glance
| type | white star (class A) |
|---|---|
| distance from the Sun | 82.6 light-years (25.3 pc) |
| its light left it | 82.6 years ago |
| luminosity | 140 × the Sun |
| radius | 4.18 × the Sun |
| surface temperature | 9,700 K |
| constellation | Ursa Major (Great Bear) |
Read off the piece’s own catalogue, the same values it draws with.
About Alioth
Alioth is a white star of class A, wider than the Sun and far more luminous. It is a chemically peculiar star with a strong magnetic field: elements gather in patches on its surface, and as it rotates those patches turn towards and away from us, so its light changes very slightly in a regular cycle.
In the Plough, Alioth is the handle star next to the bowl, between Megrez and Mizar. Like most of the Plough’s stars it belongs to the Ursa Major moving group, stars that travel through space together and probably formed together; Dubhe and Alkaid are the exceptions.
Alioth is one of the stars listed for celestial navigation, used for fixing position at sea by its height above the horizon.
What you see in the piece
Flown out to, the Plough falls apart less than most figures, because five of its stars travel together; Alioth stays near Mizar, Merak, Phecda and Megrez while Dubhe and Alkaid drift away.
Questions
What is the brightest star in the Big Dipper?
Alioth, the first star of the handle, is the brightest star of Ursa Major. It is 82.6 light-years (25.3 pc) from the Sun.