Bisdee Tier Optical Astronomy Observatory
| Bisdee Tier Optical Astronomy Observatory | |
|---|---|
| Organization | University of Tasmania |
| Location | Bisdee Tier, Spring Hill, Tasmania, Australia |
| Coordinates | 42°25′33″S 147°17′19″E / 42.42583°S 147.28861°ECoordinates: 42°25′33″S 147°17′19″E / 42.42583°S 147.28861°E |
| Altitude | 646 m (2,119 ft) |
The Bisdee Tier Optical Astronomy Observatory is an astronomical facility built by the University of Tasmania (UTAS) on Bisdee Tier, Spring Hill, Tasmania. The observatory hosts a 1.27 m optical telescope.
Telescope
The telescope has a diameter of 1.27 m (50 in). The primary mirror is made from fused silica 8 in (200 mm) thick. The mount for the telescope is equatorial. Design consists of a folded Cassegrain reflector with f/9 and 40 arcminutes of corrected field of view, image scale on focal plane is 55 micrometres/arcsec. Telescope beside standard Cassegrain focus has also two Nasmyth focal stations for additional instrumentation, switched with a remote control.
The telescope was constructed at Mr Harlingten's workshops in Norfolk, Vancouver and Tucson, Arizona. Worth 2 million Australian dollars was donated to the University of Tasmania by an anonymous businessman.
The telescope will be eventually automatized with remote control via microwave link from the University campus allowing control from all over the world by internet.
Dome
The main focus of dome design is its thermal properties – the aim is to maximally lower air turbulence generated by the building and the telescope and to ensure the telescope temperature is as close to ambient temperature as possible. The dome has low thermal capacity with forced ventilation. The control building is located in the observer's quarters, lying a distance from the dome, connected by an open-sided, roofed corridor.
Site
Previous, UTAS owned, observatory on Mt. Canopus was heavily light polluted by the nearby city of Hobart, this led to a need for choosing new site for the astronomical observations from Tasmania. Location in Southern Midlands region of Tasmania was chosen, under Dr John Greenhill's advisory, for its low light-pollution, low atmospheric turbulence (seeing) and good weather compared to average Tasmanian conditions. The observatory is at elevation of 646 metres and located about 1 hour drive from Hobart. Median seeing at the site is about 1.3 arcsec.
Instruments
- In 2011 mosaic 8192×8192 pixels OGLE-III camera will be installed with collaboration with Optical Gravitational Lensing Experiment (OGLE) team in the primary folded Cassegrain focus. Camera consist of 8 thin SITe 2048×4096 CCD chips. The pixel scale is 0.27 arcsec/pixel giving the field of view of 37 arcmin x 37 arcmin. Readout noise is 6-9 electron at gain of 1.3 e/ADU with Readout time of 98 seconds.
- additional camera (SITe 512x512 pixel CCD) will be moved from Mt. Canopus after its closure.
- 10 channel filter wheel
- fibre-fed Coude spectrograph with SITe 1024x1024 CCD camera working with two modes: low (R~1000) and high resolution (R~20,000)
- high speed EM CCD photometer
The first light will be taken in mid-2011.
Science
The main scientific goal of the new telescope will be survey and follow-up observations of microlensing events. Observations of Magellanic Clouds and Milky Way structures will be carried out. The large database of photometric measurements will give the opportunity for studying variable stars. Fast photometer will be used for measuring short time occultations of small celestial bodies.
