The frequency distribution of PG 1657+416, a rapidly pulsating sdB star

We analyse the frequencies shown by the recently discovered pulsating sdB star PG1657+416. It has at least four frequencies in the range 6.8–7.8mHz, which are used to constrain the log g value of the star. Moreover, we derive an estimate of the radial order of the modes on the basis of the observed frequency distribution.