  We investigate the dynamics of bright matter wave solitons in spin-1
Bose-Einstein condensates with time modulated nonlinearities. We obtain soliton
solutions of an integrable autonomous three-coupled Gross-Pitaevskii (3-GP)
equations using Hirota's method involving a non-standard bilinearization. The
similarity transformations are developed to construct the soliton solutions of
non-autonomous 3-GP system. The non-autonomous solitons admit different density
profiles. An interesting phenomenon of soliton compression is identified for
kink-like nonlinearity coefficient with Hermite-Gaussian-like potential
strength. Our study shows that these non-autonomous solitons undergo
non-trivial collisions involving condensate switching.
