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This report describes and analyses observations of the brighter or more interesting comets discovered or at perihelion during 2015, concentrating on those visually observed. Magnitude parameters are given for all comets with observations. Any evolution in the magnitude parameters of those periodic comets with multiple returns is discussed. Additional information on the comets discussed here, and on other comets seen or at perihelion during the year, may be found on the Comet Section’s visual observations web pages.

In this paper we examine the western branch of the Apennine Bench Formation using LROC WAC and NAC images, Clementine multispectral data, the Chandrayaan-1 Moon Mineralogy Mapper (M3), Selene images, the LROC WAC-based GLD100 digital terrain model and terrestrially-obtained CCD images. The study discusses several volcanic features, which are identified as lunar domes and small lunar cones with associated pyroclastic deposits; a possible relationship between them is investigated. We assess the regional geology and provide insight into the distribution and stratigraphy of the volcanic activity which has occurred in the region. Based on the boundaries of the Apennine Bench Formation we argue the presence of a possible megadome extending for 120km and with an average slope angle ξ of 0.5°. Finally, based on CCD telescopic images and the GLD100 dataset, we describe the morphometric properties of four volcanic constructs including their classification.

This paper describes an easy-to-use online form and database for the submission of white light and hydrogen alpha observations to the BAA Solar Section. The graphical output enables an observer to track variations in solar activity over long periods of time, based on their own observations – an advantage over the previous Microsoft Excel-based approach.

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.

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.

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.

The twelve-year lightcurve of the nova-like cataclysmic variable HS 0506+7725 between 2006 April & 2018 November is presented. This shows that the star spends most of the time in a normal state at about magnitude 14.7, but multiple excursions to a fainter state at magnitude 16.0–17.0 were apparent. These normal-state/low-state transitions of up to 2.3 magnitudes are typical of the VY Scl subclass of CVs. In the case of the best characterised fading episode, both the fading and the subseqent return to normal brightness were observed; the complete transition lasted about 43 days. Further monitoring of this system by amateur astronomers is encouraged to identify and characterise future low states.

Using observations submitted to the BAA Solar Section, the largest sunspot groups of Solar Cycle 24 are discussed and example images shown. The characteristics of the cycle are also described and a comparison is made between the sizes of its larger sunspot groups and those of previous cycles, stretching back over 100 years.

Multicolour broadband photometry and flux-calibrated low-resolution spectroscopy, obtained between 2014 & 2018, are used to investigate the behaviour of the highly variable Herbig Ae star RR Tauri.

John Glasby was a popular Director of the BAA Variable Star Section from 1965–’71; an exciting period during which George Alcock discovered three novae. Glasby’s legacy is still felt today, because he steered the Section towards more observations of cataclysmic variables as well as starting a binocular variable star programme. He also wrote three books on the subject of variable star observing, filling a major gap in the literature, along with hundreds of works of pulp fiction. Unfortunately, so much controversy surrounded major errors in his BAA reports that any positive contribution he did make has long since been forgotten. This paper is an attempt to unravel the complex enigma of John Glasby’s directorship and the set of unfortunate circumstances that damaged his astronomical reputation.