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The Journal of the British Astronomical Association, 2019 October

Volume 129, Number 5

Explore the enigmatic Gyulbudaghian's Nebula, read expert guidance on observing November's transit of Mercury, and catch up with the latest from all the Sections in the annual Council report.

Log in or join the BAA today to view this journal online. A full list of contents is also available.

Selected highlights from this Journal:

Refereed Papers

The opposition of Mars, 2012: Part I
A team of 110 observers contributed nearly 6,000 observations at this aphelic opposition. Part I discusses albedo features and dust storms, as well as some highly unusual terminator events. Following the 2007 global dust storm, a number of albedo markings were still returning to their customary shapes. Solis Lacus had not yet recovered its 2005 form, but E. Noachis and many other features had returned to normal. There was a succession of minor dust storms over and around the N. polar cap in 2012 January–April, while it was just possible to detect the aftermath of a regional storm centred upon Hellas that had been imaged from martian orbit in 2012 November.
Richard McKim
The many faces of Gyulbudaghian’s Nebula
Gyulbudaghian’s Nebula is one of a small number of nebulae that clearly changes in appearance on timescales of months or years. It is associated with the pre-main sequence star PV Cephei and can take on a range of appearances. When PV Cephei is dim, only a faint and diffuse nebulosity is visible with CCDs, but at other times it can be detected in a 0.35m telescope visually. We report on the changes within the nebula observed from 2009 July to 2015 November by members of the BAA Deep Sky Section, using a diverse range of telescopes and cameras. Most of the observations were undertaken without filters, but they have been scaled and resampled to provide indicative trends in brightness for different parts of the nebula.
Grant Privett, Andrea Tasselli, Andrew Luck, Bob Garner, Dale Holt, Daniel Self, Geoff Thurston, Mike Harlow, Owen Brazell & Steven Goldsmith
Latitude movements of solar prominences, 2010–’17
Prominence latitudes were used to track the positions of solar magnetic field boundaries over eight consecutive years. Equatorial zone boundaries moved towards the solar equator, accompanying sunspot active regions, until solar activity began to decline. Polar zone boundary migration towards the solar poles coincided with N/S magnetic field reversal, with polar ‘crowns’ forming in 2013/2014. Day-to-day prominence positions delineated field boundary orientation, which changed appreciably as the solar cycle progressed.
Fred Nye