The Pulsation Mode of the Cepheid Polaris

A previously-derived photometric parallax of 10.10±0.20 mas, d=99±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 <Mv>=-3.07±0.01 s.e., average effective temperature of <Teff>=6025±1 K s.e., and intrinsic color of (<B>-<V>)o=0.56±0.01 s.e., which match values obtained previously from the photometric parallax for a space reddening of E(B-V)=0.02±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.