arċana is a special, personal, abbreviated puja done by temple priests in which the name, birth star (nakśatra) and family lineage (gotra) of a devotee are recited to invoke individual guidance and blessings. Priests chant 21 names of the deity at whose sannidhi (shrine) the arċana is being performed.
It can be performed on any day to recognize a special event / occasion such as a birthday, anniversary, starting a new job/project, etc. The arċana does not have to be confined to any festivities. By sponsoring an arċana, the devotee is getting the divine’s blessings for that specific event / occasion.