Algedi is the brighter of a naked-eye pair at the head of Capricornus, a yellow star whose companion on the sky lies far behind it in space.
At a glance
| type | yellow star (class G) |
|---|---|
| distance from the Sun | 106 light-years (32.4 pc) |
| its light left it | 106 years ago |
| luminosity | 39.3 × the Sun |
| radius | 6.97 × the Sun |
| surface temperature | 5,480 K |
| constellation | Capricornus (Sea Goat) |
Read off the piece’s own catalogue, the same values it draws with.
About Algedi
Algedi is the brighter of the two stars that share the name Alpha Capricorni, a star of class G that is wider and far brighter than the Sun: a star that has left the main sequence and grown. A telescope shows it has faint companions of its own.
Sharp eyes see a second star beside it, Prima Giedi, the other Alpha Capricorni. The two are not a pair at all: they merely lie in the same direction, the other much further off. The name comes from the Arabic al-jady, “the goat” or “the kid”, for the head of the sea goat.
What you see in the piece
The naked-eye pair is a pure effect of perspective. In the piece Algedi sits relatively close to the Sun while its apparent twin falls far behind it as soon as you leave Earth.
Questions
Is Algedi a double star?
Algedi looks like a double to the naked eye, but its apparent partner lies much further away. The two only line up as seen from Earth.