Northamptonshire Natural History Society

Astronomy Section

Section President
Nick Hewitt
Section Secretary
James Whinfrey

Clusters and Variables

Karen Holland

I became interested in astronomy around 1994, whilst taking a career break to be with my children, and became involved with the astronomy group at Leicester University - in particular working with Dr Richard Jameson to conduct filtered CCD photometry of a number of M-class supergiants in the Perseus double cluster. When this work came to an end, I was offered the opportunity to analyse some existing data on the Praesepe star cluster, obtained at some of the world's major observatories. This work involved the dynamical modelling of the star cluster; although the broader aim of the work was to look for clusters which are likely to harbour significant populations of brown dwarf stars. The work produced very interesting and surprising results, which are summarised in my poster (below), which I presented at a conference in Sicily, and which were subsequently published (2000 MNRAS.319.956H). At home, during this period I was making visual estimates of variable stars, using a 10-inch Newtonian telescope loaned to me by the British Astronomical Association.

The Hourglass Nebula taken by the Hubble Space Telescope

I later began photometric observations using a CCD and camera lens with a filter attached to the front, and used this set-up to contribute photometry of a spectroscopic eclipsing binary star to a professional project that aimed to measure an independent distance to the Pleiades cluster. This was considered an important measurement, as the Hipparcos measured distance to the Pleiades, and the distance as indicated by models of stellar evolution, vary greatly.

In October 2001 I won a Royal Society Industry Fellowship, which enables me to conduct research in the astrophysics group at Leicester two days per week, whilst working for our CCD camera business the remaining three days per week. The Fellowship will allow me to adapt and use an XCAM camera system to obtain results that will be used to support and modify theoretical models of cataclysmic variables, constructed by scientists at Leicester University. In order to make best use of this opportunity I bought a Meade LX200 telescope, and I am currently working on setting it up to carry out good filtered photometry, using a BAA filter box. Further details of the SS Cyg project, which is my primary interest, are provided on the BAA Variable Star Section web page, in the new CCD target list that I have compiled. The Meade is currently living in a temporary housing whilst awaiting a good permanent observatory.

I have been Editor of the BAA Variable Star Section circulars since 1996, and am currently involved in several projects in this Section. In particular I have recently set up the Variable Star Section CCD target list. I have recently initiated the VS Mentor scheme, and we have just had our first meeting of the CCD Database Working Party, in order to begin considering the issues concerned with archiving BAA Variable Star Section CCD data.

I regularly present talks at local schools and societies, and am just beginning to work with Moulton School, Northampton, which has recently become one of the first Science and Technology Colleges in the country, on the National Schools Observatory programme, through their new 'Space Club'.

Image credits: Stellarium (background image)

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26 May 2014 (v 22)