This is an Iridium Flare, a line of light made by a satellite of the Iridium cluster of satellites moving overhead.
The domes of the Perth Observatory can be seen in the foreground of this fisheye photograph. The bright glow to the left is the unfortunate effect of light pollution spreading from the suburbs of Perth.
|Iridium Flare over Perth Observatory with Pleiades, Jupiter and Orion|
Also visible in the photograph is Pleiades (also called the Seven Sisters), Jupiter, and the constellation of Orion along with Sirius (the brightest star in the night sky).
Here is another photo taken a little later with nicer composition of the foreground, showing a third observatory dome in the foreground. The stars has a nice colour diffusion around them due to slight dew on the camera lens.
|Pleiades, Jupiter, Orion and Sirius at the Perth Observatory|