  Magneto-optical trap (MOT) at narrow (weak) transition offers lower
temperature and hence is the key for production of high phase density atomic
cloud and subsequently quantum degeneracy with high number of atoms for many
elements. In this paper, we describe loading of $^{87}$Rb atoms in the MOT
using a narrow open transition at 420 nm from the routinely implemented MOT
using broad cyclic transition at 780 nm (IR). The total linewidth of the blue
transition, 5S$_{1/2} \rightarrow $ 6P$_{3/2}$ is 1.4 MHz, which is around 4
times narrower than the standard 5S$_{1/2} \rightarrow$ 5P$_{3/2}$ cyclic
transition. Using this narrow transition, we have trapped around $10^{8}$ atoms
in the MOT with a typical temperature of around $54~\mu$K. We have also studied
the behavior of the blue MOT with various parameters such as hold time,
detuning and power of trapping and repumper beams.
