Members' Observations

Introduction

The Society has a long history of variable star observing from its formation, since when members have contributed several thousand observations to the BAA Variable Star Section.  Indeed, Roger Pickard is now Director of the BAA  VSS.

Most types of star have been observed and some long runs on a number of Mira stars have been accumulated, particularly, T Cas and V Cyg.  Some members have also studied a number of cataclysmic variables.

Both experienced observers and newcomers are encouraged to participate in variable star observing, and at one time almost a third of the Society’s membership had made at least a few observations.  Since the late 1980's though, photoelectric photometry has been the prominent form of observing with the result that the number of visual observations has declined.

Observations, both photoelectric and visual, are regularly reported, not only to our own membership, but to the BAA VSS as well.

Our own programme of observation parallels that of the VSS with objects suitable for large telescopes, binoculars and even the naked eye observer being included.

A further activity connected with variable stars is encoding the observations into computer form for subsequent analysis.  Members undertake this work on behalf of the BAA. Of particular importance was the entering of the complete data set of the BAA observations from 1890 of W Cygni.  John Howarth undertook an analysis of this star's behaviour, the results of which were published as a paper in JBAA (see the separate list of the Society’s published papers).  This work was subsequently awarded the top prize of £1,000 by the Star Gazers Trust for the most meritorious paper published by amateurs.

More recently, Terry Miles has taken on the role of entering all new variable star observations reported to the BAA VSS in paper form. In addition, the complete VSS Archive has been transported to Crayford for safe storage.  The entering of old observations in to the database has also been taken on by other members of the Society.

On 1st September 1999 Roger Pickard took over the role as Director of the BAA Variable Star Section from Gary Poyner (see link below).  Therefore, all matters concerning variables stars within the BAA can be addressed to him.

The Hewitt Camera Archive has been used to determine the variability of stars following requests from professional astronomers.  To date, this has not met with considerable success, partly due to the fact that the stars searched for have been a little on the faint side.  Nonetheless, one paper has been published by Dr Chris Lloyd of the Rutherford Appleton Laboratory using data from the Archive. (See IBVS 4645)

Links: See also Gary Poyner's Home Page for many interesting graphs.

Photoelectric Photometry

The Society has been active in the use of photoelectric photometry since the 1980's and has hosted several conferences and 'teach-ins' on the subject at which professional astronomers have participated.

Jack Ells, assisted by his son Peter, and Roger Pickard were practising photoelectric photometry (PEP) by 1984 and undertaking the timing of minima of short period eclipsing binaries.

Following this, Jack designed and constructed a semi-automatic telescope (APT) which is described in the JBAA (see separate list of publications).  This has become the most productive instrument in the UK for determining the behaviour of short period variables.

Since Jack Ells' death in 1990, the APT has been located near Maidstone where Society member Malcolm Gough endeavours to ensure that it operates on every clear night, either following stars on the BAA programme of eclipsing binaries, or undertaking special studies of objects requested by professional astronomers.

Roger Pickard, who wrote the review article on PEP in the JBAA (see separate list of publications), and who shared second prize in the Star Gazer's Trust competition for his work on VW Cephei, is also continuing his photometric work.

Since Jack Ells' death in 1990, the APT has been located near Maidstone where Society member Malcolm Gough endeavours to ensure that it operates on every clear night, either following stars on the BAA programme of eclipsing binaries, or undertaking special studies of objects requested by professional astronomers.  Roger Pickard, who wrote the review article on PEP in the JBAA (see separate list of publications), and who shared second prize in the Star Gazer's Trust competition for his work on VW Cephei, is also continuing his photometric work.

Collaboration with Others

For some years observations have been carried out with the Jack Ells APT and by Roger Pickard with his 16" (40 cm) Newtonian on the star X Per. Kevin West (kwest @ ryde.prestel.co.uk) on the Isle of Wight has also been following this star and has obtained far better coverage as can be seen in the graph to the right.

CCD Photometry

The use of CCD's for photometry has attracted the Society's attention and Roger Pickard is currently testing his Starlight Xpress CCD to see how accurate it is when undertaking photometry.  His first satisfactory result was obtained on the RS CVn star RT And as part of a campaign to monitor a number of these stars being coordinated by Prof James Sowell of Georgia Institute of Technology. A graph of the result is shown here.