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The Great Filter Debate took place in the BAA in the 1950s. As the writer was involved in the experiment, members of the Association may find the following account of interest.

Cycles of fading and revival of the South Equatorial Belt (SEB) are the most spectacular large-scale events that occur on Jupiter. The most recent started in 2009, when the SEB suddenly ceased its convective activity and began to fade. Modern amateur images, combined with measurements by the JUPOS team, have revealed several new insights into the process. In this pair of articles, I synthesise all the important results of the 2010 Fade (this paper) and Revival (following paper).

Bipolar magnetic regions (BMRs) are the underlying cause of all photospheric and chromospheric solar activity including active sunspot regions, white light faculae and disturbances in the solar granulation. This paper describes how monochrome imaging with commercially available H-alpha telescopes can reveal intricate detail in BMRs.

Saturn’s rings were open to their maximum extent upon the southern face. Significant new spot activity began in the South Tropical Zone and the South Equatorial Belt Zone. The STropZ activity took the form of small white spots at Saturnicentric latitude −35°, with a mean drift rate of +0.5°/day with respect to System III. White spots in the SEBZ showed a drift rate of −8.0°/day versus System III, while there was continuing evidence for a relatively slow drift in the S. Equatorial Current. A historical survey of STropZ activity is included in an Appendix, which includes previously unpublished BAA data for the 1971−’72 apparition.

An overview is presented of how to perform visual interferometry of double stars using an interference mask placed over the aperture of an undriven telescope. The purpose of the paper is to demonstrate that interesting and worthwhile observations can be obtained from a basic setup using a small telescope, thereby hopefully encouraging others to pursue this interesting field of astronomy.

In July 2015 Ricardo Hueso Alonso and colleagues discovered a bright spot on Neptune at latitude −41° with the 2.2 metre telescope of the Calar Alto Observatory. This paper reports observations and monitoring of this feature by amateur observers in the Netherlands and shows that with current amateur telescopes and digital cameras, bright features on distant Neptune can be detected and analysed.

This report describes and analyses the observations of the brighter or more interesting comets discovered or at perihelion during 2009, concentrating on those with visual observations. Magnitude parameters are given for all comets with observations. Additional information on the comets reported here and other comets discovered or at perihelion during the year may be found on the Section visual observations web pages.