On the age of LBDS 53W091

Empirical evidence suggests that the stellar population in the z=1.552 galaxy LBDS 53W091 is significantly younger than that in M32. Population synthesis models indicate that the age of LBDS 53W091 is in the range from 1 to 2 Gyr and depends on the specific model. Older ages require sub-solar metallicity models. The estimates of the age of the dominant population in M32 range from 3 to 5 Gyr and depend not only on the model but also on the SED of this galaxy used in the fits. The same models predict an age of 11 to 13 Gyr for the stars in a typical old E/S0 galaxy. A 1 to 2 Gyr old galaxy at z=1.55 poses no problem for the Λ=0, Ω=1 universe, as long as h⩽0.8. The most likely reason for the difference between our age estimate for LBDS 53W091 and the value of 3.5 Gyr derived by Dunlop et al. (1996), is the fact that, surprisingly, these authors did not require the models to fit the observed R−J, R−H, and R−K colors.