Supporting amateur astronomers since 1890
The southern boundary of Mars’ North Polar Hood (NPH) was measured from 585 Earth-based images made between 2001 and 2016. This analysis covers the late summer, autumn and winter seasons for Mars’ northern hemisphere.
Read moreWe describe a method for deriving Cousins Rc magnitudes from r, B, and V stellar photometry in the UCAC4 catalogue, valid in the range 9 < Rc < 16. The source of the majority of UCAC4 reference star photometry is the AAVSO Photometric All-Sky Survey (APASS) catalogue. Version 433 of the software Astrometrica is updated so that, provided the UCAC4 catalogue is selected as the reference, Rc magnitudes are calculated using our derived transformation, namely: Rc= r – 0.108(B–V) – 0.132.
Read more
James Henry Worthington became a prominent amateur astronomer during the years preceding the Great War, mainly because of his expeditions to distant solar eclipse tracks and observatory sites, but also because of his interest in the Martian ‘canals’ and his friendship with Percival Lowell. Just prior to the start of the War he built a major observatory at Four Marks in Hampshire, which he generously invited BAA members to use whenever they wished, at least until he moved permanently to the USA.
Read more
IntroductionWhat makes for a really good night of observing? An obvious answer is that the skies should be clear, but
Read more
All being well, members who receive their Journal through the post should have noticed something rather different about this issue.
Read more