Multiple Patchy Cloud Layers in the Planetary-mass Object SIMP 0136+0933

Abstract

Multiwavelength photometry of brown dwarfs and planetary-mass objects provides insight into their atmospheres and cloud layers. We present near-simultaneous J - and K _s -band multiwavelength observations of the highly variable T2.5 planetary-mass object, SIMP J013656.5+093347. We reanalyze observations acquired over a single night in 2015 using a recently developed data reduction pipeline. For the first time, we detect a phase shift between J - and K _s -band light curves, which we measure to be $39\buildrel{\circ}\over{.} {9}_{-1.1}^{+3.6}$ . Previously, phase shifts between near-infrared and mid-infrared observations of this object were detected and attributed to probing different depths of the atmosphere, and thus different cloud layers. Using the Sonora Bobcat models, we expand on this idea to show that at least two different patchy cloud layers must be present to explain the measured phase shift. Our results are generally consistent with recent atmospheric retrievals of this object and other similar L/T transition objects.

Keywords

• Brown dwarfs
• T dwarfs
• Exoplanet atmospheres
• Exoplanet atmospheric variability
• Exoplanet atmospheric structure
• Stellar atmospheres