Photometry in southern tail of the Antennae

We resolve individual stars and identify two stellar populations. Hundreds of massive stars are present, concentrated into tight OB associations on scales of 200pc, with ages ranging from 2 to 100Myr.

An older stellar population is distributed roughly following the outer contours of the neutral hydrogen in the tidal tail; we associate these stars with material ejected from the outer disks of the two spirals. The older stellar population has a red giant branch tip at I=26.5+/-0.2 from which we derive a distance modulus (m-M)_0_=30.7+/-0.25. The implied distance of 13.8+/-1.7Mpc is significantly smaller than commonly quoted distances for NGC 4038/4039.