Rigel is one

• Bright, blue-white heavenly body
• Rigel, for one
• Massive, relatively hot luminous body
• Spectral body
• Spectral type
• It's massive and relatively hot
• Rigel or Spica, by spectral type
• Rigel, for example

Wikipedia Word definitions in Wikipedia
BSTAR is a way of modeling aerodynamic drag on a satellite in the SGP4 satellite orbit propagation model. Traditionally, aerodynamic resistance ("drag") is given by $$F_D = \frac{1}{2} \rho C_d A v^2$$ where ρ is the air density , C is the drag coefficient ...