SIMBAD references

We present the results of new near-infrared observations of the fields around a sample of 19 Herbig Ae/Be stars. The observations reveal the population of young stars that accompanies the formation of intermediate-mass stars. The richness of the detected star clusters is investigated. We find a clear dependence of the richness of the cluster on the spectral type of the Herbig Ae/Be star, confirming that the mode of formation of intermediate-mass stars represents the transition between the high-mass and the low-mass modes. In particular, we find that the cluster nature of star formation appears at a significant (i.e. detectable) level for stars of B7 spectral type or earlier.