February 20, 2014
Billion Ton Asteroid Smashes Into Tiny Star In Puppis Constellation
[ Watch the Video: Fight Between Tiny Star And Giant Asteroid ]
Lee Rannals for redOrbit.com - Your Universe Online
Scientists say PSR J0738-4042, a star located in the constellation of Puppis, has been hit with an asteroid that had a mass of about a billion tons. The team used CSIRO's Parkes Observatory telescope and another telescope in South Africa to make the discovery.
The environment around PSR J0738-4042 is full of radiation and violent winds of particles. The team says that if a large rocky object can form in these harsh conditions, then it means planets could form around any star.
The tiny star is a pulsar, emitting a beam of radio waves towards Earth. As the pulsar spins, its radio beam flashes, creating pulses that can be witnessed by astronomers on Earth.
Previously, the team predicted how asteroids would affect a pulsar, saying it would alter the slowing of the pulsar’s spin rate and the shape of the radio pulse seen from Earth.
"That is exactly what we see in this case," Dr Ryan Shannon, CSIRO astronomer and member of the research team, said in a statement. "We think the pulsar's radio beam zaps the asteroid, vaporizing it. But the vaporized particles are electrically charged and they slightly alter the process that creates the pulsar's beam."
The authors wrote that the pulse shape changed multiple times between 1998 and 2012, adding that the torque changed abruptly from September 2005 and on.
“No known intrinsic pulsar processes can explain these timing and radio emission signatures,” the team wrote in a paper, published in the The Astrophysical Journal Letters. “The data lead us to postulate that we are witnessing an encounter with an asteroid or in-falling debris from a disk.”
The scientists say that asteroids around a pulsar could be created by an exploding star that helped form the pulsar. The material blasted from this supernova could fall back towards the pulsar to form a disk of debris. Astronomers have discovered a dust disk around another pulsar known as J0146+61.
"This sort of dust disk could provide the 'seeds' that grow into larger asteroids," Paul Brook, a PhD student co-supervised by the University of Oxford and CSIRO who led the study, said in a statement.
Scientists discovered two planet-sized objects around a pulsar known as PSR 1257+12 back in 1998. However, the astronomers said these objects were most likely formed by a different mechanism than the one they have described in the journal.