WADHURST ASTRONOMICAL SOCIETY

NEWSLETTER June 2002

INDEX: MEETINGS, OTHER NEWS, CONTACTS,

MEETINGS

LAST MEETING

As mentioned in the last newsletter, the meeting held on June 12 had a change of speaker to the one advertised. The society was lucky enough to have Alan Drummond attend the meeting and he gave a talk on the subject of Open Clusters. The talk started with an introduction to what an Open cluster actually is. They can contain any number of stars from a few dozen to a few thousand, all stars in a cluster will appear to move together and they will all have a common origin. There are about 1000 known Open clusters, but there are very likely many more that cannot be detected because of distance and luminosity. Alan bought along a number of slides of various Open Clusters that can be seen, these included; The Pleiades, M7 & M6, The double cluster in Perseus and the Hyades. The stars that make up the familiar Plough shape in Ursa Major are also part of an Open Cluster although it is very dispersed.

After the usual break for refreshments Alan continued the talk with a detailed look at measurements that can be made on individual stars in a Cluster. There are five measurements that can be made, Apparent Magnitude, Colour Index (b-v), Radial Velocity, Proper Motion and Parallax. From these measurements it is possible to plot a Hertzsprung-Russell diagram that enables the age of the cluster to be estimated. The distance can also be calculated by using the distance modulus. Alan also went into the formation of a Cluster and mentioned that many stars originally formed as part of a cluster. All clusters will disperse over time and so this is why not all stars are associated with a cluster.

Sean gave the society a talk on the subject of the Virgo supercluster.

NEXT MEETING

The July meeting is to be held on Wednesday 10th at the usual time of 7:30, in the drama studio at Uplands. The speaker this month will be Andrew Robertson and the subject of the talk is Telescopes and Optics. One aspect of Andrews's talk will be about the different types of telescope that are available. It is hoped that the society will be able to display at least one of each type on the evening, although we are still seeking owners of a Schmidt Newtonian and a Schmidt Cassegrain who are willing to bring their telescope to the meeting. If you have one of these and are willing to bring it to the July meeting please let the Editor know in advance if possible.

This meeting will be the last one before the usual summer break during August. The next meeting will be held on Wednesday 11 September. We will of course be having the summer Barbeque, further details will be in the next newsletter.

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OTHER NEWS

SPELDHURST FETE

The Society supported this event held on June 22, with a team of nine accompanied by eight telescopes, a sun scope, a display of some first class photographs and a raffle ticket drum. Excellent sun projections were conducted using as many as four instruments at any one time. These were made the more interesting by the mixture of whisps and small lumps of cloud that hurried across a sunny sky. The breeze experienced at ground level was in the region of force 5. It was gratifying that so many visitors came for a viewing. A display is expected to be made at the July meeting of the 19 unique Sun eclipse pictures produced by Peter Prince. They could well be of value to the fashion trade! Some 100 or so drops of rain fell in two light sprinklings of 30 seconds each. These turned the excellent images into unusual designs of interest and no small amusement to the public. They may well have stimulated a late flurry of activity in the sale of tickets to our raffle. Members will be pleased to learn that a young boy from Speldhurst won the Tasco Refractor and he intends to make use of it. The other prizes were a one year membership to WAS and a Constellation Umbrella. The sale of 194 tickets gives some indication of the interest shown in our exhibition.
It was well worth the effort to have participated in this fete, which was certainly well organised. Thanks to Tim for lining us up for it.

The team consisted of: Tim Bance, Valerie and Murray Barber; Thelma and Duncan Goulding; Peter Prince, Ian Reeves, Sean Tampsett and Mike Wyles. All of whom got slightly sunburnt.

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CONTACTS

Chairman: Murray R. Barber 01892 654618 murray.barber@virgin.net

Secretary: Tim Bance 01732 832745 timbance@hotmail.com

Treasurer: Ian Reeves 01892 784255

Editor: Peter Bamblett 01732 368656 pbamblett@hotmail.com

Web site: Rob Cray rob@arcray.net

Publicity: Michael Harte 01892 783292 michael@greenman.demon.co.uk

Dir. of Obs.: Sean Tampsett 01892 667092 sean_tampsett@hotmail.com

Librarian: Joan Grace 01892 783721

Custodian of Equipment: Peter Prince 01892 836284

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COPY FOR THE NEXT EDITION OF THE NEWSLETTER TO REACH THE EDITOR BY 29 JULY 2002