STAR-FORMATION IN THE OUTER RESONANCE RING OF NGC-1300

Surface photometry of the barred galaxy NGC 1300 in B and I bands reve als an outer pseudo-ring with star formation knots located at the posi tions of 10(8) M(circle dot) H I clouds previously mapped by M. Englan d with the VLA. The age of the ring from the B-I colors is estimated t o be similar to 10(9) yr, and the age of the star formation knots is e stimated to be similar to 2 x 10(7) yr. Stability considerations sugge st that the H I clouds formed by gravitational condensation along the ring periphery. If the outer extent of the ring is at the outer Lindbl ad resonance, then the bar ends slightly outside the inner 4:1 resonan ce and corotation is at the position of the break and dust lane crossi ng midway out in the spiral arms.