フォーマルハウトb
At the optical wavelengths at which Fomalhaut b is detected, it is only about 2.7×10−10 times as bright as the star and is the faintest (intrinsically) extrasolar object yet imaged. The shape of its spectrum, as determined from measurements obtained at 0.4 to 0.8 μm, appears similar to that of its host star, suggesting that the emission identifying Fomalhaut b is completely due to scattered starlight. Although the initial discovery paper for Fomalhaut b suggested that its optical brightness may be variable due to planetary accretion, later reanalyses of these data fail to find convincing evidence that Fomalhaut b is indeed variable, thus eliminating evidence for planetary accretion. However, longer-term monitoring of Fomalhaut b may show evidence that the object is fading with time.