Photometry and spectral energy distributions (SEDs) for the π¹ Gru system. Interstellar or circumstellar reddening are neglected. The gray crosses are VizieR ultraviolet to mid-infrared photometry of the full system. The gray continuous line shows the ISO spectra. Black arrows indicate VLT/SPHERE-ZIMPOL upper detection limits of the C companion (68% confidence). The red dot and blue square denote the integrated spectral flux density from the ALMA Band 6 continuum map for the primary and the C companion, respectively. The red curve represents a MARCS S-type SED for a star similar to π¹ Gru A without circumstellar dust. The yellow and orange curves correspond to PHOENIX SEDs for a G0V (B companion), and a K1V (C companion) MS star, respectively. The orange shading shows the uncertainty on the C companion properties under the MS star scenario. The blue curve corresponds to the WD scenario for the inner companion. For more details see Sect. 3.5.