The Journal of the British Astronomical Association

Volume 117, No.1: 2007 February

Summary contents page

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

On the cover: The Sun in hydrogen-alpha light

Top: montages by Pete Lawrence; left: 2006 September 17 at 09:34 UT; right: 2006 Sept. 11, 08:23-08:46 UT. Centre and bottom: images by Damian Peach; left: 2006 Sept 18; right: 2006 Sept 30, 09:20 UT; bottom: 2006 Sept 30, 09:30.

Notes and News

From the President (Richard Miles ) / Observing Venus in 2007 (Richard McKim) / Deep Sky Section (Stewart Moore ) / Solar Section (Lyn Smith) / Asteroids & Remote Planets Section (Roger Dymock) / Milan Stefanik and the rotation period of Venus: a centenary for 2007 (Richard McKim)

Photo: Comet C/2006 M4 (SWAN) imaged on 2006 October 24 by Martin Mobberley. A three-frame mosaic with a Celestron 14 at f/7.7, Paramount ME + SBIG ST9XE CCD.

Refereed articles

Insights into enthusiasm: The 1897-1898 Venus notebooks of P. B. Molesworth ... Richard Baum

Two notebooks in the possession of the Association containing three series of observations of the planet Venus in 1897-1898 by P. B. Molesworth, discoverer of the Great South Tropical Disturbance on Jupiter in 1901, are described and their contents summarised for the first time. Molesworth's unpublished report of the first series is printed as an Appendix.

Photo: The 12.5-inch (32cm) Calver installed in the garden of Molesworth's quarters at Trincomalee (Sri Lanka) in 1898 March, with which he conducted his third series of Venus observations.

CG Draconis - a particularly active dwarf nova ... Jeremy Shears, Roger Pickard & Gary Poyner

The dwarf nova CG Draconis was intensively monitored during 2005 as part of the Variable Star Section's Recurrent Objects Programme and seven outbursts were detected. These observations were combined with others from the BAA and AAVSO databases which confirmed that the star shows frequent outbursts with a period of around 11 days. Two types of outburst have been detected: short outbursts lasting about 4 days and long outbursts lasting about 8 days.

Determination of the superhump period of the dwarf nova V701 Tau during the 2005 December superoutburst ... Jeremy Shears & David Boyd

We report new measurements of the superhump period of the UGSU-type dwarf nova V701 Tauri during the 2005 December superoutburst. Using unfiltered time series CCD observations on 3 nights, we determine a probable superhump period of 0.0690 0.0002d, but note that our data also permit a possible shorter period of 0.0663 0.0002d. The longer period agrees with the value measured during the first recorded superoutburst in 1995.

The retrofocally corrected apochromatic dialyte refracting telescope ... John Wall & Peter Wise

One hundred and eight years have passed since Ludwig Schupmann took out a patent on an 'Optical correcting device for refracting telescopes'. The Schupmann telescope did not supersede or even compete with the classical refractor, although a fifteen-inch version was made for a German observatory. There the matter has stood until the present day. Schupmann telescopes are made by enthusiastic amateurs, and some find application in specialised astronomical optics; but this type of telescope, also known as a 'Dialyte', never became a major force in telescope design. The authors of this paper describe how their long term research into practical dialyte design has resulted in a 21st century alternative to the classical refractor.

The parallactic angle and the solar observer ... Peter Meadows

This paper describes the orientation of the Sun when using an altazimuth telescope mounting, which depends on the time of day as well as the solar declination. Also explained is how the solar disk cardinal points are rotated by the parallactic angle.

Click here to obtain a PDF file of any of these articles

Index to volume 116 (2006) ... R. A. Marriott


  • An observation of 'mock moons' ... Lee Macdonald
  • Asteroid data in the BAA Handbook ... Bob Dryden, Roger Dymock
  • M. V. Lomonosov and the aurora borealis ... Ron Livesey
  • More on seeing Mercury ... John C. Vetterlein
  • The role of the visual observer ... Tony Markham
  • The star of Bethlehem ... Rod Jenkins

  • Observers' Forum

  • The Messier star clusters of Auriga ... Stewart L. Moore
  • Naked eye observations of asteroid (7) Iris ... Richard Miles

  • [Photo of M37 by Cliff Meredith]


  • Ordinary Meeting, 2006 January 25 ... Martin Mobberley, Doug Ellison & Hazel McGee
  • The 7th BAA Observers' Workshop, 2006 February 25 ... Kevin Smith
  • Ordinary & Special General Meetings, 2006 March 22 ... Dominic Ford

  • Reviews

  • The Stargazer of Hardwicke (The life and work of Thomas William Webb) by Janet & Mark Robinson (eds.)
    Gracewing Publishing (2 Southern Ave., Leominster, Hereford. HR6 0QF), 2006. ISBN 0-85244-666-7. Pp xxiv + 260, 14.99 (hbk).
    Reviewed by Don Miles
  • Meteor showers and their parent comets by Peter Jenniskens
    Cambridge University Press, 2006. ISBN 0-521-85349-4. Pp xi + 790, 85.00 (hbk).
    Reviewed by Jonathan Shanklin
  • The birth of stars and planets by John Bally & Bo Reipurth
    Cambridge University Press, 2006. ISBN 0-521-80105-2. Pp x + 295, 25.00 (hbk).
    Reviewed by Nick Hewitt

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