Searching for the nature of stars with debris disks and planets

DE LA REZA, R.; CHAVERO, C.; ROCA-FÀBREGA, S.; LLORENTE DE ANDRÉS, F.; CRUZ, P.; CIFUENTES, C

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2023

0004-6361

The nature of the few known solar-mass stars simultaneously containing debris disks and planets remains an open question. A numberof works have shown that this property appears to be independent of planetary masses as well as of stellar age, but possible correlationswith stellar kinematics and metallicity have not been investigated. In this paper, we show that the majority of known stars containingboth debris disks and planets belong to the metal-enriched Galactic thin disk. The few exceptions are stars that seem to be born inthe star formation peak occurring in times of thick disk formation (i.e., HD 10700, HD 20794, and HD 40307), that is, between 11 and8 Gyr. The mass of the dusty disk of these three old stars measured at 70 µm is very small – in fact, it is lower than that of the Kuiperbelt of our Solar system by several orders of magnitude. These results are not surprising, as they remain within the values expectedfor the stellar disk evolution of such primitive stars. In parallel, we found another six thick-disk stars containing only debris disks orplanets. These results enable us to establish a correlation between stellar metallicity and the mass of the dust disk modulated by thedifferent formation epochs of the thick and thin Galactic disks.