TY - JOUR
T1 - Is There a Planet around β Pictoris? Perturbations of a Planet on a Circumstellar Dust Disk. 2. The Analytical Model
AU - Lazzaro, Daniela
AU - Sicardy, Bruno
AU - Roques, Françoise
AU - Greenberg, Richard
PY - 1994
Y1 - 1994
N2 - The evolution of micrometer-sized circumstellar grains orbiting β Pictoris is studied, taking into account the combined effects of first order resonances due to a hypothetical planet and the dissipative effect due to Poynting-Robertson drag, We first derive the averaged equations of motion of the grain near a resonance, and we describe qualitatively and quantitatively the capture into the resonance (mechanism of entrance, time scales for capture, etc.). It appears that the probability of capture cannot be derived analytically, because of the nonadiabaticity of the motion at the entrance into the resonance, at least for micrometer-sized particles and planet masses smaller than about one saturnian mass. We show that the capture of a grain into a resonance critically depends (i) on the orbital eccentricity and (ii) on the value of the critical argument of resonance just at the entrance into the resonance. Maps of capture/noncapture regions vs these two parameters are derived numerically for the 1:2, 2:3, and 3:4 resonances. They show the complexity of the capture regions, and indicate that uranian or larger planets are able to trap most of the grains into the 1:2 resonance, while ∼5 Earth masses are sufficient to trap grains into the 3:4 resonance for any grain with initial eccentricities smaller than a few percent. These results underline the dynamical importance of small planetary objects embedded in circumstellar dust disks.
AB - The evolution of micrometer-sized circumstellar grains orbiting β Pictoris is studied, taking into account the combined effects of first order resonances due to a hypothetical planet and the dissipative effect due to Poynting-Robertson drag, We first derive the averaged equations of motion of the grain near a resonance, and we describe qualitatively and quantitatively the capture into the resonance (mechanism of entrance, time scales for capture, etc.). It appears that the probability of capture cannot be derived analytically, because of the nonadiabaticity of the motion at the entrance into the resonance, at least for micrometer-sized particles and planet masses smaller than about one saturnian mass. We show that the capture of a grain into a resonance critically depends (i) on the orbital eccentricity and (ii) on the value of the critical argument of resonance just at the entrance into the resonance. Maps of capture/noncapture regions vs these two parameters are derived numerically for the 1:2, 2:3, and 3:4 resonances. They show the complexity of the capture regions, and indicate that uranian or larger planets are able to trap most of the grains into the 1:2 resonance, while ∼5 Earth masses are sufficient to trap grains into the 3:4 resonance for any grain with initial eccentricities smaller than a few percent. These results underline the dynamical importance of small planetary objects embedded in circumstellar dust disks.
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U2 - 10.1006/icar.1994.1041
DO - 10.1006/icar.1994.1041
M3 - Article
AN - SCOPUS:0002540850
SN - 0019-1035
VL - 108
SP - 59
EP - 80
JO - Icarus
JF - Icarus
IS - 1
ER -