(a) A classical Cepheid variable has mass and radius . Using the pulsation constant…

PHYSICS · Subjective · Fermi University Physics · Astrophysics & Cosmology · Stellar structure, energy generation and evolution · Stellar structure, energy generation and evolution

Stars from the Inside, Ch Pulsating stars: the kappa mechanism, the Leavitt law and asteroseismology

Problem

(a) A classical Cepheid variable has mass M=6 M⊙M = 6\,M_\odot and radius R=60 R⊙R = 60\,R_\odot. Using the pulsation constant Q=0.040 dQ = 0.040\,\mathrm{d} calibrated from Delta Cephei, estimate its radial fundamental pulsation period. (b) A different, non-radially oscillating star has νmax⁡=50 μHz\nu_{\max} = 50\,\mu\mathrm{Hz}, Δν=5.0 μHz\Delta\nu = 5.0\,\mu\mathrm{Hz} and Teff=4900 KT_{\rm eff} = 4900\,\mathrm{K}. Using the asteroseismic scaling relations calibrated to the Sun (Δν⊙=135 μHz\Delta\nu_\odot = 135\,\mu\mathrm{Hz}, νmax⁡,⊙=3090 μHz\nu_{\max,\odot} = 3090\,\mu\mathrm{Hz}, Teff,⊙=5777 KT_{{\rm eff},\odot} = 5777\,\mathrm{K}), find its mass and radius.

Browse the problem library