Context. The study of star formation is extremely challenging, due to the lack of complete and clean samples of young nearby clusters
and star-forming regions. The recent Gaia DR2 catalogue complemented with the deep ground-based COSMIC DANCe catalogue
o ers a new database of unprecedented accuracy to revisit the membership of clusters and star-forming regions. The 30 Myr open
cluster IC 4665 is one of the few well-known clusters of this age and it is an excellent target where evolutionary models can be tested
and planetary formation studied.
Aims. We provide a comprehensive membership analysis of IC 4665 and study the following properties: empirical isochrones, distance,
magnitude distribution, present-day system mass function, and spatial distribution.
Methods. We used the Gaia DR2 catalogue together with the DANCe catalogue to look for members via a probabilistic model of the
distribution of the observable quantities in both the cluster and background populations.
Results. We obtained a final list of 819 candidate members that cover a 12.4 magnitude range (7 < J < 19:4). We find that 50%
are new candidates, and we estimate a conservative contamination rate of 20%. This unique sample of members allows us to obtain
a present-day system mass function in the range of 0.02–6 M , which reveals a number of details not seen in previous studies. In
addition, we find that a spherically symmetric spatial distribution is favoured by our final list of members for this young open cluster.
Conclusions. Our membership analysis represents a significant increase in the quantity and quality (low contamination) with respect
to previous studies. It o ers an excellent opportunity to revisit other fundamental parameters such as age