Papers – Page 19 – British Astronomical Association

A. A. C. Eliot Merlin: a brief biography

A. A. C. Eliot Merlin (1860−1946) was a prolific observer and writer who enjoyed a long professional career in the British Diplomatic Service. No proper account of his life has ever been given, and the recent gift of one of his notebooks to the BAA archive prompted this short account of his career and astronomical achievements. Observing under the clear skies of Volo, Thessaly in Greece he was able to make long continuous series of observations of several bright novae, and his records of Nova Persei (1901), Nova Geminorum (1912) and Nova Aquilae (1918) were particularly complete. Merlin’s generosity to the BAA is remembered through the annual award of the Merlin Medal and Gift.

AR 12536: An unusual bipolar sunspot group

Observations of a highly tilted bipolar sunspot group from 2016 April and May are presented together with confirmation of the bipolar nature of the group based on magnetograms from the Solar Dynamics Observatory.

Staying ahead of the curve: progress in British variable star astronomy

The 2016 Presidential Address, given on 2016 Oct 26 at Burlington House, Piccadilly, London W1. The BAA Variable Star Section is the world’s longest established organisation for the systematic observation of variable stars, formed in 1890. Its database contains nearly 3 million measurements going back to 1840 and is an important resource for researchers. The aim of this Address is to reveal some of the lesser known tales that lie deep within the database, bringing to life stories about some of the people involved, especially in the early years, including Joseph Baxendell, Mary Adela Blagg and Arthur Stanley Williams, as well as shedding light on some of the stars observed. Finally we look to the future as the VSS builds on the legacy of its forebears, ensuring that it always stays ‘ahead of the curve’.

Supernova 2012fr and the distance to NGC 1365

BVRI and unfiltered MicroObservatory CCD observations of SN 2012fr covering the first 100 days following its discovery are reported.

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.