Tähtitieteellinen yhdistys Ursa
There is so much to observe that it is not possible for one person to effectively observe all kinds of phenomena. Ursa has 16 observing and technical sections and working groups: The Sun; Observation instruments; Atmospheric optics; Club and association activities; The Moon, planets and comets; Mathematics and information technology; Meteors; Storm chasing; Minor planets and occultations; Aurorae; Deep sky; Satellites and rocket phenomena; Variable stars; CCD-observations; Weather and observing conditions and Weather calendar.
All sections help to coordinate the work of amateurs, giving advice and collecting observations. Sections also interact with each other and have cooperating activities. The most important form of cooperative activities is the Cygnus summer meeting.