The brighter comets of 2006

A report of the Comet Section. Director (1990 − 2015): J. D. Shanklin. This report describes and analyses observations of the brighter or more interesting comets discovered or at perihelion during 2006, concentrating on those with reported visual observations. Magnitude parameters are given for all comets with observations.

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David Elijah Packer: cluster variables, meteors and the solar corona

David Elijah Packer (1862-1936), a librarian by profession, was an enthusiastic amateur astronomer who observed from London and Birmingham. He observed variable stars, meteors and nebulae, on one occasion reporting a brightening in the nucleus of the galaxy M77. However, his remarkable claims in 1896 that he had photographed the solar corona in daylight were soon shown to be flawed.

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The eclipsing binary HS0705+6700 binary and the search for circumbinary objects

HS0705+6700 (also identified as V470 Cam) is a short period (2.3 h) post-common envelope detached eclipsing sdB binary system which exhibits transit time variations (TTVs) of a cyclical nature. We report a further 25 timings of light minima and show that our new TTVs support and extend this cyclical pattern to 1.6 periods. We examine possible causes of the observed TTVs and confirm that the presence of a third, and possibly a fourth, body could provide an elegant explanation of these cyclical variations. However other non-circumbinary mechanisms, e.g. Applegate magnetic dynamo effects, will remain possible contenders until sufficient data has been accumulated to demonstrate that the periodicity of the TTVs is time independent. A further 27 eclipse timings recorded between 2014 October and 2015 April are reported in the Addendum. These new timings occurred 0.00012 days (~10s) later than anticipated by our circumbinary model. Two possible explanations are offered.

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Kitchen table collimation of a Cassegrain-type reflector

A method of daytime collimation of a Cassegrain-type reflecting telescope is described, which uses a circular target aligned on the optical axis of the primary mirror. Basic construction details are given for making a suitable target and a procedure is outlined for collimating both Schmidt–Cassegrain and Ritchey–Chrétien telescopes.

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The controversial pen of Edwin Holmes

Edwin Alfred Holmes (1839-1919) is best remembered for his discovery of a bright comet in 1892, now known as Comet 17P/Holmes. An amateur astronomer and authority on optics, he was an original member of the BAA and contributed to its Journal and meetings for many years. As a prolific writer of letters to English Mechanic, he developed a reputation for his controversial and acerbic penmanship.

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HW Boötis: an enigmatic cataclysmic variable star

We present the 13-year lightcurve of HW Boo between 2001 May and 2014 May. We identified 12 outbursts, which typically lasted 2 to 5 days, with an amplitude of 2.7 to 3.6 magnitudes. We discuss whether HW Boo might be a dwarf nova of the SU UMa family or an Intermediate Polar, but further observations are needed to support classification.

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