Explaining Planetary-Rotation Periods Using an Inductive Method

The Diversity of Planetary Systems Architectures: Contrasting Theory with Observations

We develop a semi-analytical model for computing planetary system formation with the aim of explaining the observed diversity of planetary systems architectures and relate this primordial diversity with the initial properties of the disc where they were born. We adopt different initial conditions based on recent results in protoplanetary discs observations, to generate a variety of planetary systems and analyze them statistically. We explore the relevance of the mass and size of the disc, its metallicity, the mass of the central star and the time-scale of gaseous disc dissipation, in defining …

The Origin and Shaping of Planetary Nebulae: Putting the Binary Hypothesis to the Test

Planetary nebulae (PNe) are circumstellar gas ejected during an intense mass-losing phase in the the lives of asymptotic giant branch stars. PNe have a stunning variety of shapes, most of which are not spherically symmetric. The debate over what makes and shapes the circumstellar gas of these evolved, intermediate mass stars has raged for two decades. Today the community is reaching a consensus that single stars cannot trivially manufacture PNe and impart to them non spherical shapes and that a binary companion, possibly even a sub-stellar one, might be needed in a majority of cases. This theo…

Planet formation from the ejecta of common envelopes

The close binary system NN Serpentis must have gone through a common envelope phase before the formation of its white dwarf. During this phase, a substantial amount of mass was lost from the envelope. The recently detected orbits of circumbinary planets are likely inconsistent with planet formation before the mass loss.We explore whether new planets may have formed from the ejecta of the common envelope and derive the expected planetary mass as a function of radius.We employed the Kashi & Soker model to estimate the amount of mass that is retained during the ejection event and inferred the pro…

On the origin of planets at very wide orbits from the re-capture of free floating planets

In recent years several planets have been discovered at wide orbits (>100 AU) around their host stars. Theoretical studies encounter difficulties in explaining their formation and origin. Here we propose a novel scenario for the production of planetary systems at such orbits, through the dynamical recapture of free floating planets (FFPs) in dispersing stellar clusters. This process is a natural extension of the recently suggested scenario for the formation of wide stellar binaries. We use N-body simulations of dispersing clusters with 10-1000 stars and comparable numbers of FFPs to study this…

Stellar multiplicity affects the correlation between proto-planetary disc masses and accretion rates: binaries explain high-accretors in Upper Sco

In recent years a correlation between mass accretion rates onto new-born stars and their proto-planetary disc masses was detected in nearby young star-forming regions. Although such a correlation can be interpreted as due to viscous-diffusion processes in the disc, highly-accreting sources with low disc masses in more evolved regions remain puzzling. In this paper, we hypothesise that the presence of a stellar companion truncating the disc can explain these outliers. Firstly, we searched the literature for information on stellar multiplicity in Lupus, Chamaeleon~I and Upper Sco, finding that r…

利用ALMA的蛇夫座盘巡天（ODISEA）：行星驱动的子结构统一演化序列解释盘形态多样性

The Ophiuchus DIsk Survey Employing ALMA (ODISEA): A Unified Evolutionary Sequence of Planet-Driven Substructures Explaining the Diversity of Disk Morphologies

该研究基于ODISEA巡天，通过结合PLANETALP与RADMC-3D代码模拟，提出并重现了行星驱动的原行星盘子结构统一演化序列，解释了盘形态多样性，支持子结构的行星起源并为探测隐藏行星提供可能。