Formed in 1890, the British Astronomical Association has an international reputation for the quality of its observational and scientific work. Membership is open to all persons interested in astronomy.
Objectives
The encouragement of all aspects of observational astronomy and the association of observers at all levels for mutual help.
The promotion of a general interest in astronomy for beginners as well as for the more advanced.
The circulation of current astronomical information and observational material.
The support of modern advanced techniques for observation, data handling and scientific presentation of results.
The presentation of medals and prizes in recognition of outstanding contributions to astronomy.
Recent Developments On Saturn
The last few weeks have seen some interesting developments in Saturn's atmosphere. Although major storms rare, smaller spots do appear from time to time which can be observed with amateur equipment.
A white spot has been visible in the South Tropical Zone (STropZ) during this apparition. However over the last few weeks this has been joined by a second white spot at the same latitude. Both have been observed visually and recorded digitally with telescopes of 20 cm aperture or larger.
(Figures: Top - 28 April 2008. Image by Ian Sharp using a C11 Schmidt Cassegrain. This shows the two spots in the STropZ.Bottom - 2 May 2008. Image by David Arditti using a C14 Schmidt Cassegrain. This
also shows both of the two STropZ spots plus the fainter spot between
the components of the SEB. - Click on the image for a bigger view)
At the beginning of May, the two spots were separated by approximately 20 degrees of longitude. The original spot is at a system 3 longitude of approximately 300 degrees whereas the newer spot is at a longitude of approximately 320-324 degrees. The longitude of the Saturn's central meridian in system 3 for any date / time may be derived from the tables given in the BAA Handbook or by use of the WinJupos software. This information may then be used to assess if the appropriate longitudes are visible at the time of observation. At the time of writing this note (9 May 2008), the second spot has now become brighter than the first and further changes seem to be in progress.
In addition, another fainter spot has also been reported between the two components of the South Equatorial Belt (SEB). This appears to have a rapid drift relative to system 3. During the last apparition, a white spot was observed in the same region and showed a similar rapid drift.
Additional observations of all of these features are required in order to follow any further changes and such observations may be submitted into the Saturn section.
