Astronomy & Astrophysics

Table 1: Relevant parameters of the calibrators of Achernar. $\oslash _{\rm UD}$ is the equivalent uniform disc angular diameter. The value of $\oslash _{\rm UD}$ for $\delta$ Phe and $\chi$ Phe is based on spectrophotometry (Cohen et al. 1999), while that for $\alpha$ PsA was measured separately with the VLTI and should appear in a forthcoming publication from one of us (E.F.).
Table 2: Fundamental parameters for two limit solution models of Achernar. From the fixed parameters and in the Roche approximation, the minimum polar inclination is $i_{\min} = 46\hbox{$^\circ$ }$ where $V_{\rm eq}=V_{\rm crit}=311$ km s^-1 and $R_{\rm eq}=1.5~R_{\rm pol}$ . In addition to these parameters we adopted a linear limb darkening coefficient from Claret (2000) compatible with the variable effective temperature and gravity over the stellar surface. The equatorial effective temperature is much lower than the polar one due to the von Zeipel effect.