Sirius A is the brightest star in the night sky, a hot white star made dazzling less by its power than by how close to the Sun it sits.
At a glance
| type | white star (class A) |
|---|---|
| distance from the Sun | 8.6 light-years (2.64 pc) |
| its light left it | 8.6 years ago |
| luminosity | 25.4 × the Sun |
| radius | 1.71 × the Sun |
| surface temperature | 9,940 K |
| constellation | Canis Major (Great Dog) |
Read off the piece’s own catalogue, the same values it draws with.
About Sirius A
Sirius is a white main-sequence star, hotter, larger and much more luminous than the Sun, burning through its fuel far faster. It is not exceptional among stars; it shines brightest of all in our sky because it is one of the nearest. It marks the nose of Canis Major, the Great Dog, and is still called the Dog Star.
Its brightness gave it a place in many cultures. In ancient Egypt its first appearance before dawn, after a season hidden in the Sun’s glare, came near the start of the Nile’s flood and helped mark the year.
Sirius is not alone. Friedrich Bessel noticed it wavering along its path across the sky and concluded that an unseen companion was pulling on it. That companion, Sirius B, was later seen through a telescope and turned out to be a white dwarf, the collapsed remains of a star.
What you see in the piece
Fly to it and the white dwarf Sirius B appears beside it, so faint next to its companion that it is lost in the glare until you are close.
Questions
How far away is Sirius?
Sirius is 8.6 light-years (2.64 pc) from the Sun, so the light you see tonight left it 8.6 years ago.
Why is Sirius so bright?
It gives out 25.4 × the Sun’s light, and it is one of the nearest stars, at 8.6 light-years.