The Pulsation Mode of the Cepheid Polaris

Autor:	Turner, David G., Kovtyukh, V. V., Usenko, Igor, Gorlova, N.
Rok vydání:	2012
Předmět:	Astrophysics - Solar and Stellar Astrophysics Astrophysics - Astrophysics of Galaxies
Druh dokumentu:	Working Paper
DOI:	10.1088/2041-8205/762/1/L8
Popis:	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 =-3.07+-0.01 s.e., average effective temperature of =6025+-1 K s.e., and intrinsic color of (-)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. Comment: To appear in ApJL
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1211.6103 Zobrazit plný text záznamu View this record from Arxiv