2005/03/21 by Chadwick H. Young, Neal J. Evans, Neal J. Evans II · 3 citations
Chemistry · Physics and Astronomy · #Astrophysics and Star Formation Studies #Molecular Spectroscopy and Structure #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/430436
published as Astrophys.J. 627 (2005) 293-309 · accepted ApJ
arxiv created 2005/03/21 · openalex publication_date 2005/06/27 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
We present an evolutionary picture of a forming star. We assume a singular isothermal sphere as the initial state of the core that undergoes collapse, as described by Shu. We include the evolution of a first hydrostatic core at early times and allow a disk to grow, as predicted by Adams & Shu. We use a one-dimensional radiative transfer code to calculate the spectral energy distribution for the evolving protostar from the beginning of collapse to the point when all envelope material has accreted onto the star + disk system. Then, we calculate various observational signatures ( T bol , L bol / L smm , and infrared colors) as a function of time. As defined by the bolometric temperature criterion, the Class 0 stage should be very short, while the Class I stage persists for much of the protostar's early life. We present physical distinctions among the classes of forming stars and calculate the observational signatures for these classes. Finally, we present models of infrared color-magnitude diagrams, as observed by the Spitzer Space Telescope , that should be strong discriminators in determining the stage of evolution for a protostar.