Eta Cassiopeiae A is a nearby star very much like the Sun, slightly brighter, with an orange dwarf companion, in the familiar W of Cassiopeia.
At a glance
| type | yellow star (class G) |
|---|---|
| distance from the Sun | 19.4 light-years (5.95 pc) |
| its light left it | 19.4 years ago |
| luminosity | 1.24 × the Sun |
| radius | 1.05 × the Sun |
| surface temperature | 5,970 K |
Read off the piece’s own catalogue, the same values it draws with.
About Eta Cassiopeiae A
Eta Cassiopeiae A, named Achird, is a main-sequence yellow star close to the Sun in temperature, size and brightness. It has a fainter companion, Eta Cassiopeiae B, an orange dwarf on a wide, slow orbit around it.
Because it is so similar to the Sun and so close, it has long been a reference for comparing Sun-like stars. It sits in Cassiopeia, near the bright stars of the W, and from northern latitudes can be seen all year.
What you see in the piece
With HUMAN EYE on it is a modest point among the brighter stars of Cassiopeia. Fly to it and the companion appears beside it, smaller and more orange.
Questions
How similar is Eta Cassiopeiae A to the Sun?
Very similar: its luminosity is 1.24 × the Sun, its radius 1.05 × the Sun and its surface temperature about 5,970 K.