The Journal of the British Astronomical Association

Volume 121, No.3: 2011 June

Detailed contents: Notes and News / Articles / Observers' Forum / Reviews / Letters / Meetings / BAA Update

Cover image
Peter Carson imaged the Crescent Nebula, NGC 6888, using a Tele Vue NP101 f/5.4 refractor. The image is a combination of 80min H-alpha obtained from his home observatory in Leigh-on-Sea, Essex and 30min each RGB from Kelling Heath, Norfolk. See article on p.174.

Notes and News

From the President (David Boyd) / ‘Back to Basics’ in Macclesfield: a huge success! (Tony Morris) / Aurora Section (Ken Kennedy) / Observations of supernova 2011B in NGC 2655 (Guy M. Hurst) / More supernova discoveries for BAA members (Stewart L. Moore) / Solar Section (Lyn Smith) / The BAA archives – an appeal for original material (Dick Chambers) / The Radio Astronomy Group in 2010 (John Cook)

Refereed papers

The transit of Venus, 2012 June 5–6 ... Peter Macdonald

On 2012 June 5–6 there occurs a transit of Venus across the face of the Sun, the second in the current pair of transits, with just the egress being visible from the British Isles. The transit occurs at Venus’ descending node with the planet crossing the northern part of the Sun’s photosphere. For a geocentric observer ingress occurs on June 5 at 22h 10m UT (= Universal Time, which is used throughout this paper) and egress on June 6 at 04h 50m. Figure 1 illustrates the path which Venus appears to take across the Sun for a geocentric observer. In this paper, figures depicting the solar disk have celestial north at the top and Venus moving from left to right. The planet appears as a small black disk approximately 1/32 of the Sun’s diameter, and its position is shown at intervals of one hour.

The opposition of Mars, 2005: Part I ... Richard McKim

This report analyses nearly 14,000 observations by 188 contributors during 2004 November to 2006 July. Compared with its appearance at opposition in 2003, Pandorae Fretum was dark and complete, as a result of Regional dust activity late in the previous apparition, whilst E. Deucalionis Regio and Mare Serpentis had returned to normal. Dust activity was observed around the south polar cap (SPC) periphery in 2005 July-August, especially in association with the decay of the SPC outliers Thyles Mons and Novus Mons. A Regional storm affecting the Hellas-Margaritifer Sinus-Argyre area began about 2005 June 5 (Ls= 225°), and a more significant one began in eastern Valles Marineris on October 17 (Ls= 308°) with independent bursts of activity over Solis Lacus and Aram. This major event caused only small-scale albedo changes: it also deposited dust over the SPC summer remnant. Local post-opposition dust storms were observed in Chryse-Xanthe, Aetheria, NE Arabia and NE Tempe-Mare Acidalium. As in 2003, but in contrast to 2001 and 2007, there was no planet-encircling storm during 2005. An ‘opposition brightening’ was observed upon the slopes of Olympus Mons, the Tharsis Montes and Elysium Mons. Part II will discuss white clouds and polar region phenomena.

Discovery and outburst characteristics of the dwarf nova
ASAS J224349+0809.5 ... Jeremy Shears et al.

We report the discovery of a new dwarf nova and observations of its first confirmed superoutburst during 2009 October. The outburst amplitude was 6 magnitudes. The main outburst lasted 17 days and was followed 4 days later by a remarkable rebrightening. Superhumps were present during the main outburst, which confirms that it belongs to the SU UMa family. Analysis of archival data showed that outbursts also occurred in 2005 October, 2006 June and 2007 June. Assuming that the superoutbursts are periodic, we estimate that the outburst period is around 450 days.

Measuring the white dwarf spin period of the intermediate polar
1RXS J063631.9+353537... Jeremy Shears & Ian Miller

We report unfiltered CCD photometry of the intermediate polar 1RXS J063631.9+353537, from which we determined the white dwarf spin period as P_spin= 1008.3(5) sec. Such value is consistent with the longer of two possible values of P_spin previously reported by other researchers.

The aurora in the United Kingdom, 1962–2009 ... R. J. Livesey

In 2009 only one instance of auroral light was reported, a weak apparition in northern Scotland. This prompted an examination of auroral records in the BAA’s possession to see how the aurora has behaved over the years.

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Meetings

AGM & Ordinary Meeting, 2010 October 27, held at the RAS meeting room, Burlington House, Piccadilly, London W1 ... Hazel McGee

Ordinary Meeting, 2010 November 20, held at the RAS meeting room, Burlington House, Piccadilly, London W1 ... David Arditti

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Letters

The speed of the lunar shadow on Earth during solar eclipses ... Peter Macdonald

Light pollution: plus ça change? ... Jeremy Shears

Reporting the aurora ... Ron Livesey

‘Five spiders in a Newtonian’ ... Jeremy Tatum

Reviews

Amateur radio astronomy (2nd edn) by John Fielding
Radio Society of Great Britain, 2011. ISBN 978-1-905-08667-2. pp 375, £16.99 (pbk).

Reviewed by Paul Hyde

The Cambridge atlas of Herschel Objects by James Mullaney & Wil Tirion
Cambridge University Press, 2011. ISBN 978-0-521-13817-8. pp v + 183, £27.99 (pbk, spiral bound).

Reviewed by Stewart Moore

Discoverers of the Universe: William and Caroline Herschel by Michael Hoskin
Princeton University Press, 2011. ISBN 978-0-691-14833-5. Pp xvi + 237, £20.95 (hbk).

Reviewed by Jacqueline Mitton

Galileo and 400 years of telescopic astronomy by Peter Grego & David Mannion
Springer, 2010. ISBN 978-1-4419-5570-8. Pp. ix + 300, £27.50 (pbk).

Reviewed by Mike Frost

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