map of the activities for European night of researchers on next 30 septembre

You should use umap for this. See http://umap.openstreetmap.fr/en/.

The core OpenStreetMap data is not a suitable place for relatively ephemeral information. Currently there are projects to build on OSM to provide open mechanisms for storing such ephemeral data. These are in relatively early stages of developments:

• OpenEventMap (1): http://www.openeventmap.tum.de/ looks to be not under development any more (clue is imagery provided by Cloudmade in credits). Was a student project at Technische Universität München (TUM) by Bibek Shresta. Some slides here, and summary on the wiki.
• OpenEventMap (2): http://www.openeventmap.net/. I don't know what the relationship between this instance & the previous instance, but this has current events visible, a logon/registration mechanism and is published by Daniel Nyfeler. I haven't been able to logon & edit so I cant add more.
• OpenEvent Database: https://github.com/openeventdatabase/backend/wiki. Christophe Quest (cq94) is presenting this at SotM-16 today.

Although it should be possible to integrate OpenEvent Database with umap I doubt that this has been done yet. With only 30 specific objects to add it is certainly not a major task to add them directly, and this is what I would recommend you do.