Detecting Weather Patterns on Low-Gravity Brown Dwarfs

Photometric variability monitoring is sensitive to atmospheric features as they rotate in and out of view, allowing us to probe the presence of features caused by inhomogeneous clouds and temperature fluctuations. Periodic variability has been detected in L and T brown dwarfs, and more recently in a small sample of free-floating, planetary-mass objects. These young, low-gravity objects share a striking resemblance with the directly-imaged planets and can be studied in far greater detail in the absence of a bright host star. The large amplitudes observed in this small sample of low-gravity objects suggests that variability may be enhanced for the exoplanet analogues. We have recently carried out the first large survey for weather patterns on low-gravity brown dwarfs and exoplanet analogues. I will present the results of this survey and discuss what we have learned about the role of surface gravity in variability properties