# The New Generation Planetary Population Synthesis (NGPPS). IV. Planetary systems around low-mass stars

**Authors:** Remo Burn, Martin Schlecker, Christoph Mordasini, Alexandre Emsenhuber, Yann Alibert, Thomas Henning, Hubert Klahr, Willy Benz  
**arXiv:** [2105.04596](https://arxiv.org/abs/2105.04596)  
**Date:** 2021-05-10  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/2105.04596v2/

## Key points

- The New Generation Planetary Population Synthesis (NGPPS) study investigates planet formation around low-mass stars and identifies differences in the statistical distribution of planets.
- The study uses a more holistic approach that reflects the diverse architectures of planetary systems, as current surveys routinely detect planets down to terrestrial size in these systems.
- Temperate, Earth-sized planets are most frequent around early M dwarfs and rarer for solar-type stars and late M dwarfs.
- The planetary mass distribution does not linearly scale with the disk mass due to the emergence of giant planets for M*>0.5 Msol, which leads to the ejection of smaller planets.
- For M*>0.3 Msol there is sufficient mass in the majority of systems to form Earth-like planets, leading to a similar amount of Exo-Earths going from M to G dwarfs.
- The number of super-Earths and larger planets increases monotonically with stellar mass.
- The NGPPS study further identifies a regime of disk parameters that reproduces observed M-dwarf systems such as TRAPPIST-1.
- Giant planets around late M dwarfs such as GJ 3512b only form when type I migration is substantially reduced.
- The authors quantify the stellar mass dependence of multi-planet systems using global simulations of planet formation and evolution.
- Overall, this study provides valuable insights into planet formation around low-mass stars and predicts trends that can be tested with future observations. It highlights the importance of taking a more holistic approach when studying planetary systems in order to accurately reflect their diverse architectures.

## Summary

The New Generation Planetary Population Synthesis (NGPPS) study investigates planet formation around low-mass stars and identifies differences in the statistical distribution of planets. The study uses a more holistic approach that reflects the diverse architectures of planetary systems, as current surveys routinely detect planets down to terrestrial size in these systems. The authors compare synthetic planet populations to observed exoplanets using the Generation III Bern model of planet formation and evolution, which includes planetary migration, N-body interactions between embryos, accretion of planetesimals and gas, and long-term contraction and loss of gaseous atmospheres. The study finds that temperate, Earth-sized planets are most frequent around early M dwarfs and rarer for solar-type stars and late M dwarfs. The planetary mass distribution does not linearly scale with the disk mass due to the emergence of giant planets for M*>0.5 Msol, which leads to the ejection of smaller planets. For M*>0.3 Msol there is sufficient mass in the majority of systems to form Earth-like planets, leading to a similar amount of Exo-Earths going from M to G dwarfs. In contrast, the number of super-Earths and larger planets increases monotonically with stellar mass. The NGPPS study further identifies a regime of disk parameters that reproduces observed M-dwarf systems such as TRAPPIST-1. However, giant planets around late M dwarfs such as GJ 3512b only form when type I migration is substantially reduced. The authors quantify the stellar mass dependence of multi-planet systems using global simulations of planet formation and evolution. Overall, this study provides valuable insights into planet formation around low-mass stars and predicts trends that can be tested with future observations. It highlights the importance of taking a more holistic approach when studying planetary systems in order to accurately reflect their diverse architectures.