2024/01/08 by Susanne Pfalzner, Pfalzner, Susanne, Furkan Dincer +1 · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Astrophysics of Galaxies (astro-ph.GA) #Earth and Planetary Astrophysics (astro-ph.EP) #FOS: Physical sciences #Solar and Stellar Astrophysics (astro-ph.SR) #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2401.03775
openalex publication_date 2024/01/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
While most protoplanetary discs lose their gas within less than 10 Myr, individual disc lifetimes vary from < 1 Myr to >> 20 Myr, with some discs existing for > 40 Myr. Mean disc half lifetimes hide this diversity; only a so-far non-existing disc lifetime distribution could capture this fact. The benefit of a disc lifetime distribution would be twofold. First, it provides a stringent test on disc evolution theories. Second, it can function as input for planet formation models. Here, we derive such a disc lifetime distribution. We heuristically test different standard distribution forms for their ability to account for the observed disc fractions at certain ages. Here, we concentrate on the distribution for low-mass stars (spectral type M3.7 - M6, Ms ≈ 0.1 - 0.24 Msun) because disc lifetimes depend on stellar mass. A Weibull-type distribution (k=1.78, λ=9.15) describes the observational data if all stars have a disc at a cluster age tc=0. However, a better match exists for lower initial disc fractions. For f(t=0)= 0.65, a Weibull distribution (k=2.34, λ=11.22) and a Gauss distribution (σ=9.52, μ=9.52) fit similarly well the data. All distributions have in common that they are wide, and most discs are dissipated at ages > 5 Myr. The next challenge is to quantitatively link the diversity of disc lifetimes to the diversity in planets.