What's New: July 2005

July 2005 This page was last updated in 2000 and so there is a lot to catch up on. Duncan Galloway; the group's previous web-master finished his Ph.D. and is moving to Melbourne University to take up the 2005 Centenary Fellowship, after working at M.I.T. as a post-doc. He's been working on X-ray binaries. Bob Watson retired in early 2001. Last year the department of Mathematics and Physics appointed 3 astronomers; John Dickey as head of physics, Melanie Johnson-Hollitt as a lecturer and Stefan Dieters as a lecturer. John Dickey's research interests are in radio spectroscopy of the Milky Way and other galaxies. Melanie's research focuses on radio and optical (radial velocity) observations of galaxy clusters. Stefan's research background is in studying the X-ray and optical timing and spectral properties of X-ray binaries and cataclysmic variables. Chis Hollitt also joins us on a part time basis. His background is in electronic engineering and optics.

Over the last 6 months there has been a lot of work on the hardware front. Long term observes will notice a few changes. The top hat, that covered the central buffle, is gone. It has been replaced by a flexible cover attached to the mirror petals. We have installed a cloud camera that can be accessed via the web. The guide-scope camera has been replaced with a sensitive video camera. We can now see stars down to at least 8th magnitude. A similar replacement for the through-telescope (offset) camera is ready to be installed. We decided to wait till the end of the current PLANET season to install it. The tip-tilt control system has been installed. Currently we are using it to differentially track comet Tempel 1. The next step is to drive the tip-tilt system with the auto-guider output. This should improve our guiding. After that we'll use the new offset video camera to measure pointing drifts. Also, we'll then test the tip-tilt system as a first order Adaptive Optics system i.e. remove the slow seeing. We'll keep you posted.

In late 2004 a pair of possums took up residence inside the dome. They took to sleeping inside the offset-mirror control box. That piece of electronics has now been replaced! A photo of the possum made it into UniTas magazine. Both possums have been successfully relocated. The ringtail possum has taken up residence in a new home built by John Greenhill in the bush near the observatory. The other was captured and transported across the waters of the Derwent to the Waterworks reserve. Similar to the colonization of Hobart! So if you see a possum hitching across the bridge, don't give him a lift!

Over the summer we had the main mirror and secondary re-alummized. Apparently the possum-piss didn't affect the mirror. The roller bearings on the dome were all replaced. Oh and we had a major cleanup. It's amazing what a good scrub and a coat of paint will do!

Using a University of Tasmania large projects grant the group purchased a Leach controller for our SITe 1024x1025 chip and a large grating. Chris Hollitt is now working on commissioning the new camera. This camera will become the detector for a fibre fed spectrograph at the coude focus of the telescope. Eventually we want to create a multi-fibre system for doing radial velocity measurements on galaxy clusters.

So far 2005 has been an amazing year! Before the PLANET season had actually begun we and lot of others observed OGLE-2005-BLG-071 which showed a double peaked light-curve that can only be explained by a star + planet system. The planet is estimated to be 3 times the mass of Jupiter. In Hobart, that created a bit of a local media frenzy. So the possum is not the only one in the media. Since then there's been lots of other interesting anomalous micro-lensing events. We still have 2 1/2 months to go! Also, we have been monitoring Comet Tempel 1 since mid-May and will continue till mid-September. On July 4th the public was invited to a public talk and live NASA-TV feed. It was great to see the smash live. Have a look at the In the News section for some of the local (and a bit over the top) media coverage.

Last summer (2004/2005) we continued to monitor the cataclysmic variable OY Car measuring orbital period changes. There's been a new outburst of our favourite millisecond pulsar SAX 1801.4-3658 and a new one: XTE J0924-314. We have gather BVRI photometry of both looking for near-IR flares. In conjunction with the radio astronomers at Tas Uni we are monitoring the active galaxy PKS1144-379.

Stefan Dieters

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URL: http://www.phys.utas.edu.au/physics/optastr/whatsnew.htm
20th July 2005