British Astronomical Association
Supporting amateur astronomers since 1890

Secondary menu

Main menu

The Journal of the British Astronomical Association, 2020 December

Volume 130, Number 6

Celebrating women in astronomy, Dr Mark Kidger's forecast for a well-known yet mysterious star, and the case of the vanishing nebula. Plus, try our challenging Quiz.

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:

Notes and News

Astronomy for all – all for astronomy
Claudia Antolini, Osnat Katz & Helen Usher
Comet prospects for 2021
Jonathan Shanklin

BAA Update

Observers' Forum

The Z Cam stars
Gary Poyner

Refereed Papers

Supernova Betelgeuse?
Betelgeuse has been the focus of considerable recent attention – even from the mainstream news media – due to its recent deep minimum, to the extent that 10% of all the light curve data on the star in the AAVSO archive, extending 126 years, have been obtained in just the last six months. While it is not impossible that Betelgeuse will become a supernova in the next few years or decades, what we know about the star makes this unlikely. A large part of the uncertainty comes from the fact that neither the mass nor the distance are well-established. It is not even certain that Betelgeuse will become a core-collapse supernova. Overall, the star appears to have brightened significantly over the last 60 years, but the evidence for similarly deep minima in 1946, 1947 and 1984 relies on fragmentary data and single observers. The entire extreme historical range of Betelgeuse from magnitude 0.1–1.6 appears to have occurred in just the last three years.
Mark Kidger
Maria Mitchell, the Danish comet medal & early American astronomy
Maria Mitchell (1818–1889) was the first American woman who could truly be described as an astronomer and the first American to be credited with the discovery of a comet. In the mid-19th century, much kudos was attached to finding new comets and the international recognition Mitchell received after being awarded one of the King of Denmark’s medals for her discovery contributed to raising the worldwide standing of American astronomy, adding to the momentum driving professionalised astronomy forward in the US.
Jacqueline Mitton
Eclipse time variations & the continued search for companions to short-period eclipsing binary systems
Eclipse time variations have been detected in a number of post-common envelope binary systems consisting of a subdwarf B star or white dwarf primary star, and cool M-type or brown dwarf secondary. In this paper we consider circumbinary hypotheses of two sdB systems, HS 0705+6700 (also known as V470 Cam) and NSVS 14256825, and one white dwarf system, NN Ser. In addition, and for comparison purposes, we investigate the eclipse time variations of the low-mass binary system NSVS 01286630 with its stellar circumbinary companion. All four eclipsing systems have claims of circumbinary objects with computed physical and orbital parameters. We report 108 new observations of minima for these systems obtained between 2017 May and 2019 September and combining these with all published data, we investigate how well the published circumbinary object hypotheses fit with our new data. The new data have shown departure from early predictions for three of the four systems, but it is premature to conclude that these results...
George Faillace, David Pulley, John Mallett, Americo Watkins, Ian Sharp, Xinyu Mai
The Quadrantids & December alpha Draconids 2012–2019: Multi-year meteor videography
NEMETODE, a network of low-light video cameras in and around the British Isles operated in conjunction with the BAA Meteor Section and other groups, monitors the activity of meteors, enabling precise measurement of radiant positions as well as the altitudes, geocentric velocities and solar system orbits of meteoroids. The results from observations of the Quadrantid and December alpha Draconid meteor showers during 2012–2019 are presented and discussed.
Alex Pratt