Tag Archives: gamma ray bursts

A developing new astronomical mystery

Radio astronomers in Australia have recently detected a number of new mysterious radio bursts, dubbed fast radio bursts because of their nature, coming from outside our galaxy whose cause presently has no clear explanation.

An unprecedented double burst recently showed up along with four more of these flashes, researchers report online November 25 at arXiv.org.

Fast radio bursts, first detected in 2007, are bright blasts of radio energy that last for just a few milliseconds and are never seen again. Until now, astronomers had cataloged nine bursts that appeared to originate well outside the Milky Way. Yet, follow-up searches with nonradio telescopes for anything that might be pulsing or exploding keep coming up empty.

This mystery is similar to that of gamma ray bursts (GRBs), which were first discovered in the 1960s. About once a day there would be a short burst of gamma ray energy coming from scattered random directions in the sky, but no other radiation in any other wavelength. For decades astronomers didn’t know if the GRBs were coming from just outside our atmosphere or from billions of light years away. Finally, in the 1990s they pinned their location to the deaths of stars in distant other galaxies. As noted by one scientist at a conference, “GRBs signal the daily formation of a new black hole.”

Fast radio bursts are more intriguing. Because of their wavelengths and random locations on the sky, astronomers seem confident that they are occurring outside the Milky Way. However, in the eight years since their discovery only a handful have been detected, making it extremely difficult to study them. Nonetheless, they are significant because they signal some cataclysmic event far away, likely the death of a star in a way not yet understood or predicted. Finding out what that event is will produce important information about the evolution of our universe.

It just might take decades for this new mystery to be solved. Stay tuned!

Astronomers have found evidence which suggests that most of the universe’s gold was created during the collision and merger of two neutron stars.

Astronomers have found evidence which suggests that most of the universe’s gold was created during the collision and merger of two neutron stars.

A binary of two neutron stars will eventually spiral into each other. When they do, scientists believe that their violent merger produces short gamma ray bursts (GRB). Observations of a short GRB burst in June found a lot of spectroscopic evidence of gold.

[T]he explosion had been responsible for the creation of a whole menagerie of heavy elements. They estimated that an equivalent of 1% of the sun’s matter was being flung out from the collision in a tail, and about 10 parts per million of that tail was made of gold.

Last Saturday the space telescope Swift detected the most powerful gamma ray bursts ever detected.

Last Saturday the space telescope Swift detected the most powerful gamma ray burst ever detected.

You can see the raw reports of the detection, followed up immediately by a host of other ground-based and space-based observations at this website. Click on the circulars for GRB130427A, starting with circular 14448. When this happened last Saturday I was out camping. When I got home there were dozens of circulars to look at. Based on the data here, this gamma-ray burst was relatively close for a grb, approximately 3.6 billion light years away.

New data from a neutrino telescope in Antarctica had found that cosmic rays don’t come from gamma ray bursts, as had been believed by astronomers.

The uncertainty of science: New data from a neutrino telescope in Antarctica has found that cosmic rays don’t come from gamma ray bursts, as had been believed by astronomers. You can read the paper here. [pdf]

Which means that astronomers at this moment have no idea what produces these high energy cosmic rays.