The discovery of nonradial pulsation in the λ Bootis star HD 111604

International audienceEvidence for high order nonradial pulsation (NRP) has been discovered in the λ Boo star HD 111604. Analysis of a limited number of spectra of the NaID lines indicate that the mode of oscillation, |m|, is approximately 20 and NRP features circumnavigate the star every 0.71 days. Current models suggest that these objects should be near the ZAMS, and the detection of nonradial pulsation in at least one member of the class presents the exciting possibility of performing a direct measurement of its evolutionary state to test this hypothesis