MAGELLAN AO SYSTEM z′, y _S, and L′ OBSERVATIONS of the VERY WIDE 650 AU HD 106906 PLANETARY SYSTEM

We analyze archival data from Bailey and co-workers from the Magellan adaptive optics system and present the first 0.9 μm detection (z′ = 20.3 ±0.4 mag; Δz′ = 13.0 ±0.4 mag) of the 11 M _Jup circumbinary planet HD 106906AB b, as well as 1 and 3.8 μm detections of the debris disk around the binary. The disk has an east-west asymmetry in length and surface brightness, especially at 3.8 μm where the disk appears to be one-sided. The spectral energy distribution of b, when scaled to the K _S-band photometry, is consistent with 1800 K atmospheric models without significant dust reddening, unlike some young, very red, low-mass companions such as CT Cha B and 1RXS 1609 B. Therefore, the suggested circumplanetary disk of Kalas and co-workers might not contain much material, or might be closer to face-on. Finally, we suggest that the widest (a 100 AU) low mass ratio (M _p/M _∗ ≡ q ≲ 0.01) companions may have formed inside protoplanetary disks but were later scattered by binary/planet interactions. Such a scattering event may have occurred for HD 106906AB b with its central binary star, but definitive proof at this time is elusive.