Astronomers spot new type of 'death star'
A team of astronomers have found the 'missing link' of stellar death, revealing what our Sun might look like at the end of its life.
The group of Australian and US astronomers, led by Associate Professor Miroslav Filipovic of the University of Western Sydney, call the new class of object 'super planetary nebulae'.
They report on their finding in the journal Monthly Notices of the Royal Astronomical Society.
Large stars typically end their life in a massive explosion of energy known as a supernova. Small stars end with a much smaller blast of gas and dust, known as planetary nebulae.
Planetary nebulae had only been detected around stars with a mass of between 30% and 60% that of the Sun. As a result, little was known as to what happened to average-sized star, such as our Sun.
Filipovic and colleagues stumbled upon the super planetary nebulae, during a radio search of supernova using CSIRO's Australia Telescope National Facility.
"During the process of looking for supernova remnants, these guys popped up," he says. "We went back and observed these in more detail through higher resolution."
The 15 bright radio objects, located in the Magellanic Clouds, were previously thought to be 'regular' planetary nebulae. The detection of radio waves coming from these objects confirmed the researchers had found something new.
The super planetary nebulae appear to have formed from stars that were up to eight times the mass of the Sun.
"We are shocked to see these radio emissions. We know that these are massive in terms of explosion, but not as massive as supernovas," Filipovic says.
The researchers conducted numerous observations on the super planetary nebulae to confirm their new find.
"We were holding out for three years. Every single colleague that I showed said 'No way!" says Filipovic, "So we went back with deeper and deeper observations."
"We have been holding up our findings for some three years until we were 100% sure that they are indeed planetary nebulae".
Filipovic believes planetary nebula images are the most impressive objects in the galaxy.
"When you look at the Hubble pictures, they are the sexiest pictures you can find," he says.
According to Filipovic, it's important to understand how super planetary nebulae form, particularly as they represent the fate of our Sun.
"This is something that will happen to us in about five billion years from now," he says.
Filipovic says the proposed Square Kilometre Array radio telescope, to be built in either Western Australia or South Africa, should make it possible to detect super planetary nebulae in our own galaxy.
"I am confident that we will find some of these guys in our galaxy. We just need better instruments to detect them."