Papers – Page 20 – British Astronomical Association

Short paper: Polar alignment of the equatorial mount: how accurate must it be for trail-free astrophotography?

This paper develops and presents a rule of thumb as to how accurate the polar alignment of an equatorial mount must be, in order to avoid trailing stars in astrophotography.

Short paper: Perigee lunar eclipses

Details are presented of lunar eclipses occurring very close to perigee, for the years 1000 to 3000.

Saturn in 2001 − 2002

The south face of the rings was displayed nearly to its maximum effect during this presentation. The various occultations of the planet and its satellites by the Moon were further highlights of the apparition.

Mr William Strachan and his remarkable telescope

The observing career of Mr William Strachan of Bournemouth, a BAA member from 1908 to 1935, is described. Despite severe lifelong disability he managed to regularly observe the Sun, variable stars and a few other objects for 26 years. His observing career in later life was only made possible by using a custom made polar refractor Coudé system which he used regularly from 1924 to 1934.

High resolution imaging of mutual events of the Jovian satellites during the 2014/2015 apparition

During the 2014/2015 Jupiter apparition several mutual occultations and eclipses of the Galilean satellites took place. These mutual events occur every 5.93 years. A number of the events were recorded using 14-inch [355mm] or larger telescopes and different types of cameras. Processing programs like Registax 6.1 or Autostakkert2! struggle to grade, align and stack the tiny images of the Jovian satellites. To obtain high resolution images different processing procedures were employed to optimise the quality of the images, including hand selection and the use of master frames. Several occultations and eclipses were recorded at high resolution.

The period of R Scuti

R Scuti is a variable star which, for over a century, has shown episodes of RV Tauri-type behaviour, together with significant spectral variations that appear to be associated with its brightness. This paper examines the photometric data amassed by the BAA and the AFOEV, and finds periods of nominally 71 and 142 days.

A lunar dome north-east of the crater Schröter

In this study we examine a lunar dome identified using Lunar Reconnaissance Orbiter Camera Wide-angle Camera (LROC WAC) images, Selene-1 (Kaguya) and Clementine multispectral data, the Chandrayaan-1’s Moon Mineralogy Mapper (M3), and the LROC WAC-based GLD100 DTM.

Short paper: Photometric and spectroscopic observations of the outburst of the symbiotic star AG Draconis between 2016 March and June

The symbiotic star AG Draconis experienced a double-peaked outburst of 0.6 magnitudes in 2016 April and May. Photometry and spectroscopy through the outburst showed the B-V colour index varying linearly with the V magnitude and enabled the temperature variation of the hot star to be calculated from the changing flux in the Hb and He II 4686Å emission lines.

Saturn in 2000 − 2001

In 2000-2001 Saturn was extremely well-placed for observers at north temperate latitudes, coming to opposition on 2000 Nov 19, when its declination was +17°. This paper presents and analyses BAA observations for this apparition.

The brighter comets of 2008

A report of the Comet Section (Director, 1990 − 2015: J. D. Shanklin). This report describes and analyses the observations of the brighter or more interesting comets discovered or at perihelion during 2008, concentrating on those with visual observations.