A previously-derived photometric parallax of 10.10 \pm 0.20 mas , d = 99 \pm 2 pc , is confirmed for Polaris by a spectroscopic parallax derived using line ratios in high dispersion spectra for the Cepheid .
The resulting estimates for the mean luminosity of \langle M _ { V } \rangle = -3.07 \pm 0.01 s.e. , average effective temperature of \langle { T } _ { eff } \rangle = 6025 \pm 1 K s.e. , and intrinsic color of ( \langle B \rangle - \langle V \rangle ) _ { 0 } = +0.56 \pm 0.01 s.e. , which match values obtained previously from the photometric parallax for a space reddening of E _ { B - V } = 0.02 \pm 0.01 , are consistent with fundamental mode pulsation for Polaris and a first crossing of the instability strip , as also argued by its rapid rate of period increase .
The systematically smaller Hipparcos parallax for Polaris appears discrepant by comparison .