Gacrux
Where is Gacrux?
Below the horizon from London all the time in Crux.
- Rises
- Never
- Highest
- —
- Sets
- —
- Best after dark
- —
Can I see Gacrux tonight?
Gacrux never rises from London: it is too far south in the sky for this latitude.
This is position and timing only: clouds, haze and light pollution aren’t included.
What does Gacrux look like?
Gacrux looks orange-red to the eye. Its spectral type is M3.5III: cool red giant (much cooler than the Sun).
Eyes
An orange-red star at the head of the Southern Cross.
Binoculars
Its warm color contrasts beautifully with blue-white Acrux and Mimosa.
Telescope
A bright orange point. A faint, unrelated star lies nearby.
About Gacrux
Gacrux is the top star of the Southern Cross and the nearest red giant to the Sun, about 88 light-years away.
Its orange-red color stands out clearly against the blue-white stars of the rest of the Cross.
Gacrux is many times wider than the Sun, with a cool surface of roughly 3,300 °C that gives it its color. Like many red giants, it varies a little in brightness.
It has an unusual chemistry, rich in the element barium, which may have been transferred from a companion star that is now a white dwarf.
Because it is so close, Gacrux is one of the brightest red giants in the sky. It appears, along with the rest of the Southern Cross, on the flags of Australia, New Zealand, Brazil, Papua New Guinea and Samoa.
Gacrux and Acrux together make the long axis of the Cross. Extending that line about four and a half times its length leads close to the south celestial pole, a trick sailors have used for centuries.
Gacrux in Crux
Questions
Why is Gacrux a different color from the rest of the Southern Cross?
Sources: SkyMate; Wikidata (CC0). Positions computed for your place and time with astronomy-engine. Data & Licences