Gyrochronology relations from Meibom et al. (2009; M09) and Barnes (2007; B07). The shaded region around each relation (with the same colour) represents the standard error of the relationship between (B − V)₀ and rotation period from propagating the uncertainties reported for the coefficients entering Eq. (11) together with the uncertainty in our age estimate. The vertical line and shaded region give the value of (B − V)₀ = 0.495 ± 0.022 of HAT-P-7, while darker shaded regions around the relations vertically bound the corresponding uncertainty in the period from the uncertainty in (B − V)₀, age, and the gyrochronology relations. The horizontal lines indicate the limits on the 68% (dashed) and 95% (dotted) credible regions on the stellar rotation period from p-mode splittings. The upward-pointing arrows indicate that these rotation periods are lower limits from the respective HPD credible regions.