Observational evidence for dust growth in proto-planetary discs

TL;DR

This paper reviews recent infrared observations providing evidence for initial dust grain growth in proto-planetary discs around young stars, highlighting how dust properties evolve with stellar type and environment.

Contribution

It presents observational evidence for early dust growth in proto-planetary discs, comparing different star types and environments to understand dust evolution.

Findings

Evidence of dust grain growth in proto-planetary discs

Variation of dust properties with stellar type and environment

Insights into initial stages of planet formation

Abstract

The dust in the interstellar medium, that provides the material for forming stars - and circumstellar discs as a natural by-product - is known to have submicron sizes. As these discs are the sites of planet formation, those small grains are predicted to grow to larger entities when the stars are still young. will review evidence for the first steps in grain growth in proto-planetary discs around young stars, based on recent Spitzer and ground-based infrared observations. First, I will discuss disc and dust properties in Herbig Ae/Be stars, and then move to the lower-mass T Tauri stars and the brown dwarfs. Here, objects of different star-forming regions are compared, and the influence of the stellar parameters and environment on dust evolution, as witnessed by the observed dust characteristics, is discussed.