Australia's top research observatory home to several telescopes used by scientists from around the world was under threat from wildfires on Sunday as hot weather and lightning storms stoked scores of new blazes.
The Rural Fire Service (RFS) of New South Wales, Australia's most populous state, issued an emergency warning for an out-of-control fire raging towards the Siding Spring Observatory, a remote global research facility.
"About a dozen isolated properties at Mt Woorut, including Siding Spring Observatory, may come under threat," the RFS said.
"This is a large and dangerous bush fire... Police have evacuated the area around Siding Spring. Firefighters and waterbombing aircraft are on scene."
Siding Spring, a mountain-top site in the Warrumbungle ranges about 500 kilometres (310 miles) north-west of Sydney, houses 10 operating telescopes run by Australian, Polish, British, Korean and American researchers.
Administered by the Australian National University's research school of astronomy and astrophysics, Siding Spring is the nation's major optical and infrared observatory and one of the top facilities of its kind in the world.
A university spokeswoman said all observatory personnel had been confirmed as "safely evacuated and accounted for".
"The university is working closely with the NSW Rural Fire Service and monitoring the situation," she told AFP.
Crews were battling difficult conditions, with temperatures in the area in excess of 40 degrees Celsius (104 Fahreheit) and hot north-westerly gusts blowing at about 60 kilometres (37 miles) per hour.
The fire was burning across a four-kilometre front, with a strong southerly change later in the evening expected to complicate containment efforts.
A partner observatory at Canberra's Mount Stromlo was destroyed by wildfires in January 2003 that killed four people and razed more than 500 homes.
Five telescopes, residences and more than a dozen buildings were ruined in the Mount Stromlo inferno, forcing the termination of a number of major projects including a digital survey of the southern hemisphere's skies.
Large parts of Australia have sweltered under extreme heat in the past week, sparking hundreds of wildfires that have destroyed more than 100 homes.
In the northern state of Queensland train services were halted Sunday due to fears that tracks would buckle under scorching heat that has seen bitumen road surfaces melt in some towns.
The RFS said lightning storms started about 40 new fires overnight in northern NSW, fanned by strong winds, though most were in remote areas and not a threat to properties.
By Sunday evening there were 134 fires burning across NSW, 43 of which were out of control, according to the RFS.
Wildfires are a common threat in arid Australia, particularly in the hotter months between December and February, and the government's Climate Commission has warned that global warming will increase the fire risk.
Some 173 people were killed and more than 2,000 homes destroyed during the so-called Black Saturday firestorm in 2009, Australia's worst natural disaster of modern times.