SIMP J013656.5 093347

SIMP J013656.5 +093347 is a brown dwarf in the constellation Pisces. It belongs to the spectral class T2.5 and its position shifts due to its proper motion annually by about 1.24 arcsec with a position angle of about 90°.

This brown dwarf provided the first evidence for periodic variability flux variations among T dwarfs. This has been interpreted as a signature of weather patterns coming in and out of view over the object's 2.4h rotation period. The shape of this lightcurve evolves over timescales of days, which has been interpreted as a sign of evolution of the cloud patterns in its atmosphere.