Rocks around the clock: asteroids pound tiny star

Feb 19, 2014
An artist's impression of an asteroid breaking up. Credit: NASA/JPL-Caltech

(Phys.org) —Scientists using CSIRO's Parkes telescope and another telescope in South Africa have found evidence that a tiny star called PSR J0738-4042 is being pounded by asteroids—large lumps of rock from space.

"One of these rocks seems to have had a mass of about a billion tonnes," CSIRO astronomer and member of the research team Dr Ryan Shannon said.

PSR J0738-4042 lies 37,000 light-years from Earth in the constellation of Puppis.

The environment around this star is especially harsh, full of radiation and violent winds of particles.

"If a large rocky object can form here, planets could form around any star. That's exciting," Dr Shannon said.

The star is a special one, a 'pulsar' that emits a beam of radio waves.

As the star spins, its radio beam flashes over Earth again and again with the regularity of a clock.

In 2008 Dr Shannon and a colleague predicted how an infalling asteroid would affect a pulsar. It would, they said, alter the slowing of the pulsar's spin rate and the shape of the radio pulse that we see on Earth.

"That is exactly what we see in this case," Dr Shannon said.

"We think the pulsar's radio beam zaps the , vaporising it. But the vaporised particles are electrically charged and they slightly alter the process that creates the pulsar's beam."

Asteroids around a pulsar could be created by the exploding star that formed the pulsar itself, the scientists say.

The material blasted out from the explosion could fall back towards the forming pulsar, forming a disk of debris.

Astronomers have found a dust disk around another pulsar called J0146+61.

"This sort of dust disk could provide the 'seeds' that grow into larger asteroids," said Mr Paul Brook, a PhD student co-supervised by the University of Oxford and CSIRO who led the study of PSR J0738-4042.

In 1992 two planet-sized objects were found around a called PSR 1257+12. But these were probably formed by a different mechanism, the astronomers say.

The new study has been published as a paper in The Astrophysical Journal Letters, a leading journal of astronomical research: Evidence of an asteroid encountering a pulsar.

Explore further: Hubble video shows shock collision inside black hole jet

More information: "Evidence of an Asteroid Encountering a Pulsar," P. R. Brook et al., 2014 ApJ, 780, L31. dx.doi.org/10.1088/2041-8205/780/2/L31

Related Stories

A spinning neutron star is tied to a mysterious tail

Aug 18, 2011

(PhysOrg.com) -- A spinning neutron star is tied to a mysterious tail -- or so it seems. Astronomers using NASA's Chandra X-ray Observatory found that this pulsar, known as PSR J0357+3205 (or PSR J0357 for ...

Dead star and distant black holes dazzle in X-rays

Jan 09, 2014

(Phys.org) —Two new views from NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, showcase the telescope's talent for spying objects near and far. One image shows the energized remains of a dead star, ...

A pulsar's mysterious tail

Jul 14, 2011

(PhysOrg.com) -- A spinning neutron star is tied to a mysterious tail -- or so it seems. Astronomers using NASA's Chandra X-ray Observatory have found that this pulsar, known as PSR J0357+3205 (or PSR J0357 ...

A strong magnetic field around the Milky Way's black hole

Aug 14, 2013

(Phys.org) —Astronomers have made an important measurement of the magnetic field emanating from a swirling disk of material surrounding the black hole at the center of our Milky Way Galaxy. The measurement, ...

Recommended for you

A bubbly cosmic celebration

14 hours ago

In the brightest region of the nebula RCW 34, gas is heated and expands through the surrounding cooler gas. Once the heated hydrogen reaches the borders of the gas cloud, it bursts outwards into the vacuum ...

Image: XMM-Newton self-portraits with planet Earth

14 hours ago

This series of images was taken 15 years ago, a couple of months after the launch of ESA's XMM-Newton space observatory. These unique views, showing parts of the spacecraft main body and solar wings, feature ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.