λ Boo stars as tracers of planet formation

PAULA MIQUELARENA; J. ALACORIA; DANIELA CALVO; MARTÍN GIRARDI, G.; FLORES MATÍAS

Córdoba

Congreso; XI Friends of Friends Meeting.; 2021

Instituto de Astronomía Teórica y Experimental (IATE) - Observatorio Astronómico de Córdoba (OAC)

We study the possible chemical signature of planet formation in early-type stars with planets. In particular, we analyze a likely relation between the λ Boo chemical pattern and the presence of giant planets by using spectralsynthesis. Our first sample includes 13 stars with planets and 24 stars without detected planets. We have detected four λ Boo stars in our sample, two of which present planets and circumstellar disks (HR 8799 and HD 169142)and one without detected planets (HD 110058). We also identified the first λ Boo star which is orbited by a brown dwarf (ζ Del). Our results support a scenario in which giant planets orbiting pre-main-sequeunce stars block the dust of the disk and result in a λ Boo pattern. On the other hand, we do not support a proposed scenario in which the winds form hot-Jupiter planets could produce a λ Boo pattern on early-type stars.