Untangling a Complex Young Stellar System

The top panel shows the spectrum of KH 15D during its "bright" phase, when the amount of direct starlight was greatest. The middle spectrum ("intermediate" phase) was taken when star B was just below the edge of the ring. Both spectra in the bottom panel were obtained during "faint" phases from two different cycles, when both stars were near periastron and the contribution from starlight was minimized. The spectrum from November has been offset by 1.5x10^-15 W m^-2 μm^-1 for comparison to the data from December.