Variability of the lowest mass objects in the AB Doradus moving group

摘要: We present the detection of [$3.6~\mu$m] photometric variability in two young, L/T transition brown dwarfs, WISE J004701.06+680352.1 (W0047) and 2MASS J2244316+204343 (2M2244) using \textit{Spitzer Space Telescope}. find a period $16.4\pm0.2~$hr peak-to-peak amplitude $1.07\pm0.04\%$ for W0047, $11\pm2~$hr $0.8\pm 0.2\%$ 2M2244. This is significantly longer than that measured previously during shorter observation. {We additionally detect significant $J$-band 2M2244 Wide-Field Camera on UKIRT. } determine radial rotational velocities both objects Keck NIRSPEC data. velocity $-16.0_{-0.9}^{+0.8}~$km s$^{-1}$ 2M2244, confirm it as bona fide member AB Doradus moving group. $v \sin i=9.8\pm0.3~$km s$^{-1}$and $14.3^{+1.4}_{-1.5}~$km W0047 respectively. With inclination angles $85 ^{+5\circ}_{-9}$ $76 ^{+14\circ}_{-20}$, are viewed roughly equator-on. Their remarkably similar colours, spectra inclinations consistent with possibility viewing angle may influence atmospheric appearance. \textit{Spitzer} $[4.5~\mu\mathrm{m}]$ monitoring T5.5 object SDSS111010+011613 (SDSS1110) where we no variability. For periods $<18~$hr, place an upper limit $1.25\%$ SDSS1110.