2015ApJ...807...64Q

We present the first multi-wavelength, high-contrast imaging study confirming the protoplanet embedded in the disk around the Herbig Ae/Be star HD 100546. The object is detected at L' () and M' (), but not at K_s(), and the emission consists of a point source component surrounded by spatially resolved emission. For the point source component we derive apparent magnitudes of mag, mag, and mag (3σ limit), and a separation and position angle of and, and and in L' and M', respectively. We demonstrate that the object is co-moving with HD 100546 and can reject any (sub-)stellar fore-/background object. Fitting a single-temperature blackbody to the observed fluxes of the point source component yields an effective temperature of K and a radius for the emitting area of. The best-fit luminosity is. We quantitatively compare our findings with predictions from evolutionary and atmospheric models for young, gas giant planets, discuss the possible existence of a warm, circumplanetary disk, and note that the deprojected physical separation from the host star of AU poses a challenge to standard planet formation theories. Considering the suspected existence of an additional planet orbiting at ∼13-14 AU, HD 100546 appears to be an unprecedented laboratory to study the formation of multiple gas giant planets empirically.