Hertzsprung-Russell diagram for all stars in the last snapshot (top panel) and for the 69 stars in the JWST synthetic observations (bottom panel). The small symbols (magenta and red) are for photospheric luminosities, while the large symbols (green and blue) are for stellar luminosities which include the accretion luminosity. Magenta and green points are class I stars, while red and blue points are class II. When L_acc is small (especially class II stars), the small points overlap with the larger ones, resulting in the appearance of red/magenta points with blue/green borders for class II and class I stars, respectively. The zeroage main sequence is indicated by the dashed black line, while the thin transparent light-green lines show the evolutionary tracks of all stars from an age of 10⁴ yr to the time of the snapshot, and the thin transparent light-blue lines are the evolutionary tracks with episodic accretion included. Stellar evolution is computed following the methodology of Jensen & Haugbølle (2018).