Long-term stability of 2M1721+33 across two different wavebands. At the top is the Metchev et al. (2015) Spitzer 3.6 μm light curve with their fit in red and our Gaussian process celerité2 fit in blue applied to the Spitzer and HST light curves independently. Both models fit the data very similarly. At the bottom is the HST white light curve from our work with our Gaussian process celerité2 overplotted (in green). Although these two light curves were observed over 9 years apart and at different wavelengths, they have a similar shape. They both exhibit a primary dip, followed by a secondary dip in each period. This may suggest long-term stability in 2M1721+33’s light curve.