The article originally published on pages 179 - 183 of the 2016 Astronomy in Focus Volume 11, Issue A29A, purportedly by Wesley and Sheshadri, was mistakenly included in the issue and should not have been published. During the compilation of the issue, the first page of Wesley and Sheshadri's legitimate article (Wesley & Sheshadri 2016) was combined with other pages from a wholly unrelated LaTeX file, and published in error. The content of this pseudo-article makes no sense, and should not be used or cited. Therefore, the pages of this pseudo-article have been removed from the online version of the issue and replaced with blank pages watermarked as ‘WITHDRAWN’. We have decided to remove the article completely to avoid confusion with the correct article by Wesley and Sheshadri, who were not involved in the creation of this error.

We apologise to the authors Wesley and Sheshadri, and to readers for this mistake.