Participants in the Summer School '99


Larger copy of this same picture.


Results from the Summer School '99

The attendees split themselves into six groups, each investigating one of the constituents of the night sky. The observations made by each group are described very briefly below. If any participants would like to write a paragraph or so about their project, it could be incorporated here to better describe your results.

  • Planets
  • Stars
  • Clusters
  • Luminous Nebulae
  • Dark Nebulae
  • Galaxies

  • Planets


    This is the image actually used by the group to measure the height of a mountain on the Moon.


    The seven images we took, fit together nicely to create a map of a small section of the lunar surface. This image also serves to illustrate how small a field of view is available through large telescopes such as the 74"

    Several of the individual images are also available.
    Image 1, Image 2, Image 4, Image 6.

    We also took some very quick pictures of Jupiter and Saturn. No analysis or further investigation was made of these due to lack of time, but we include them here since they are rather interesting. They very clearly show that both planets are accompanied by systems of moons. Two are visible on the Jupiter picture and many more around Saturn.
    Sorry no pictures yet. They need converting to a web friendly format before I can put them up.


    Stars

    Imagine living on a planet orbiting a star that literally explodes every 90 days! It is just such star that we have been observing for our project. The aim of our project was to find a cataclysmic eclipsing binary and determine its period, mass, rotational velocity, and distance.

    Using the megalithic resources of the net, we found a particularly variable binary star. The next step was to make 100 measurements with the 74 inch, ending with a list of 100 magnitudes. With the awesome computer power of unix and a sparc workstation, we processed these magnitudes using the stable stars around the variable as guides to compensate for cloud cover and accurately determine the light curve of our star to within .003 of magnitude. With our newly made light curve the stars' orbital rate was measured at 1.79 hours. Using assorted formulae (and a borrowed parameter or two), we found the object(s) mass, distance, and velocity of our exciting object.

    The selected star, Z Cha, is in fact a pair of stars in orbit around each other and each time one star passes in front of the other, an eclipse occurs making the star apparently dim slightly. As the stars come out of alignment, both are visible again and the brightness returns to normal. The two stars which are so close together they look like just a single star in the image. The eclipse happens extremely quickly. The min and max images below were taken only 90 seconds apart.

    I would like to thank on behalf of our team all those who assisted our project, Particularly Robert Smith, Geoff Bicknell, and Michelle Buxton. Thankyou all.

    Z Cha at Maximum

    Z Cha at Minimum

    Z Cha in False Colour

    Z Cha's Light Curve

    The magnitudes measured for Z Cha and the various reference stars in the field are here.


    Clusters

    This group wanted to plot a Hertzsprung-Russell diagram of a globular cluster. The H-R diagram is fundamental to our understanding of stellar evolution. It may be used to calculate the age of a cluster and has also been used to measure their distances. Though it is simply a plot showing each star's colour and brightness (magnitude), it has historically been and still is a very important diagnostic plot. The cluster chosen for study was NGC288.

    NGC288

    The H-R diagram produced yielded a plot showing all the usual features. The main sequence where most stars lie is in the centre, with the sub-giant branch running up to the top right and a blue horizontal branch giving the data points in the top left. We tried to find a plot in the literature to compare ours to, but noone seems to have ever published an H-R diagram of NGC288. Is this a genuine World first?


    Luminous Nebulae

    If someone gives me the data, I'll add it in here.


    Dark Nebulae


    Galaxies

    The group selected the galaxy NGC1365 and took images of it through three filters. The three images were combined and they then tried adjusting the colour balance in order to highlight certain features of the galaxy. Visible in different images are such features as the disc, the spiral arms, the bar, starburst knots and a possible Seyfert core.


    The raw data may also be inspected.
    B image, V image, R image.



    Robert J. Smith, rsmith@mso.anu.edu.au
    Last modified: Mon Jan 31 12:15:59 EST 2000