Findings:

• sigma factor
• Sigma (user)
• Sigma field
• Sigma Xi
• Sigma Alpha Epsilon
• sigma finite
• Six Sigma
• Sigma EM8500
• Sigma Alpha Mu
• Phi Kappa Sigma
• σ algebra
• Sigma Star Saga
• sigma sigma sigma
• sigma algebra
• Alpha Chi Sigma
• sigma curve
• sigma male
• 7th Sigma
• Sigma Designs
• sigma
• Σ
• Sigma Nu
• Sigma Draconis
• Sigma Phi Epsilon
• sigma notation
• Kappa Sigma
• Plateau Sigma
• Sigma Mu Beta
• Korg Sigma
• Tau Beta Sigma
• Sigma Chi
• sigma function
• Sigma Kappa
• Phi Delta Sigma

If you Log in you could create a "Sigma Octantis" node. If you don't already have an account, you can register here.