& kstars; is pretty accurate, but it is not (yet) as precise as it can possibly be. The problem with high-precision calculations is that you start having to deal with a large number of complicating factors. If you are not a professional astronomer, you will probably never have a problem with its accuracy or precision.
O & kstars; é bastante exacto, mais (ainda) non tanto como podería ser. O problema cos cálculos de precisión elevada é que se comeza a ter que tratar cun número moi grande de factores que os complican. Se non es un astrónomo profesional, probabelmente nunca teñas problemas coa súa exactitude ou precisión.