Astronomy is a very cool area, dealing with sizes which really do challenge the scope of what the human mind can deal with. It deals with the creation and formation of the Universe as we know it … and so far astronomers seem to be doing a pretty good job of figuring it all out. Another proverbial jigsaw piece has fallen into place and predictions verified; a Neutron Star has been seen in the process of turning into a Pulsar.
A neutron star transforming into a millisecond pulsar has been discovered in our galaxy confirming the evolutionary link between the two, says an Australian researcher.
Astronomers have long suspected millisecond pulsars, extremely old stars that spin up to 700 times per second emitting radio waves, evolved from neutron stars. But they have never found a star in the transition phase until now.
The discovery, published today in the journal Science, is a big boost to the ‘recycling theory’ of millisecond evolution.
The theory suggests that in a two star or binary star system, a neutron star will accrete by pulling matter from the donor star causing it to accelerate rapidly and transform into a milliseconds pulsar.
Neutron stars are remnants of a star explosion or supernova that emit x-rays.
CSIRO Australia National Telescope Facility astronomer and study co-author Dr David Champion says there are competing theories for how these pulsars can be created.
“A lot of the push for the other theories has been that we’ve never seen a pulsar in this phase before.”
Champion says the discovery of the transition star has revealed how the x-rays of the neutron star transform into the radio waves emitted from millisecond pulsars.
During accretion, x-rays are emitted from places of intense heat masking the radio waves normally emitted from the neutron star he says.
At the end of accretion phase only radio waves are emitted by the pulsar. These waves can be seen as a flash of light from Earth as the star spins.
“They actlike a lighthouse,” says Champion.
Champion says no one is really sure how long the transition from neutron star to pulsar is.
“What’s really interesting to us is that it’s changed states [from emitting x-rays to radio waves] in the last 10 years of our observations. But that’s only a very small part of the process.”
Not so ridiculous
Dr Bryan Gaensler, an astronomer from the University of Sydney, says when millisecond pulsars were first discovered in the 1980’s one group put together a “ridiculously contrived, convoluted, ad-hoc chain of arguments” of how they might be born.
“At the time most people thought ‘yeah right’,” says Gaensler. “Remarkably every step in the sequence has been born out.”
Gaensler says this discovery demonstrates that because the universe is so big and there are so many stars, anything that is possible, no matter how ridiculously improbable, is going to happen somewhere.