Physical parameters of $\mathsf{\lambda}$ Bootis stars

摘要: This is the rst of two papers whose main goal to update and improve information available on physical properties Bootis stars. The determination stellar parameters fundamental importance shed light into dierent theories proposed explain phenomenon. With this aim, projected rotational velocities, eective temperatures, surface gravities chemical abundances a sample suspected stars have been calculated. Five objects showing composite spectra typical binary systems were found in our analysis. abundance distribution program does not resemble composition class prototype, Boo, which poses some concerns regarding idea well-dened, chemically homogeneous group A possible relation between velocities phenomenon has found. result would be agreement with accretion scenario by Turcotte & Charbonneau (1993).