Star profile
Rukbat
Alpha Sagittarii · Sagittarius
Hot blue starWhat is Rukbat
Rukbat takes the Arabic 'rukbah', 'knee', and indeed marks the knee of the archer in Sagittarius, just where the centaur figure braces to draw back the bow. Although it is the alpha of its constellation, it is not the brightest member of Sagittarius: traditional names do not always follow the modern hierarchy of brightness measured in magnitudes. It is a hot blue star some 182 light-years away, its light having crossed space since 1844.
Where it is and when to see it
Rukbat lies in the southern celestial hemisphere. It is visible to the naked eye under a dark sky. Its best month of the year is July: the Sun sits at the opposite point of the sky and the star culminates around midnight. How high it climbs above the horizon depends on the latitude you watch from.
It opens in your browser. Free, no account, nothing to install.
The signature wall
Stelvia's sky works like a signature wall: anyone can leave their name and a message on a real star, and that signature goes up on the map for everyone to read. Signing is free.
A signature without a lock can be replaced by someone else's. The lock makes the signature permanent and lets you choose a symbolic name for the star, always shown next to the star's catalogue identifier. How the lock works
If you don't have an account yet, we'll ask for an email to confirm it's you: we send you a link and that's it, no password.
A public signature from a real person. The chosen name is a symbolic denomination within Stelvia, with no official standing or IAU recognition: the sky is not for sale and belongs to no one.
Astronomical data for Rukbat
- Constellation
- Sagittarius
- Apparent magnitude
- 3.96
- Distance
- 181.8 light years
- Coordinates (J2000)
- RA 290.972° · Dec -40.616°
- Catalogue
- HIP 95347 · HD 181869
A symbolic commemorative gift: neither the signature nor the chosen name implies ownership of the star or recognition by the IAU.
Other stars in Sagittarius
Sagittarius has 117 stars in Stelvia's catalogue. Here are a few of them.
- Kaus AustralisEpsilon Sagittarii1.79
- NunkiSigma Sagittarii2.05
- AscellaZeta Sagittarii2.60
- PolisMu Sagittarii3.84
- Rho 1 Sagittarii3.92
- Arkab PriorBeta 1 Sagittarii3.96
- Iota Sagittarii4.12
- Arkab PosteriorBeta 2 Sagittarii4.27