September 21, 2017

Review: What Are Gamma-ray Bursts? by Joshua S. Bloom.

Out from Princeton Press!

In 1888, astronomer Simon Newcomb made the now infamous quip that “we are probably nearing the limit of all we can know about astronomy…” One has to wonder what these 19th century scientists would make of the wonderful cosmological menagerie of black holes, energetic galactic nuclei, and the topic of today’s review. [Read more...]

07.04.11: Catching a Black Hole in the Act.

An artist’s conception of a black hole gobbling a star. (Credit: NASA/CXC/M. Weiss).

NASA’s swift spacecraft caught something interesting on the night of March 28th, 2011. Launched in 2004, the spacecraft is designed to detect extragalactic x-ray and gamma-ray flashes. And what a flash they caught in GRB 110328A; a burst four billion light years distant that peaked at a brightness one trillion times that of our own Sun. But what’s truly interesting was that the power curve seen by astronomers was consistent with a galactic mass black hole devouring a star. Word on the astro-street from the Bad Astronomer, Phil Plait is that a yet to be released set of Hubble follow up images of the region seem consistent with the burst occurring near the core of a distant galaxy. In addition, NASA’s Fermi satellite, which also watches for gamma-ray bursts, has detected no past activity from the galaxy in question; this was an individual event without precedent. Did astronomers witness a “death by black hole” of a star? Perhaps such an event could occur if a nearby passage of another star put the body on a doomsday orbit. And interesting side note; astronomers established a thread to track GRBs in another pair of science/astronomy blogs that you might have heard of, the Bad Astronomy/Universe Today bulletin board. Much of the initial discovery and follow-up action occurred here, a forum worth following. And they say, “What good is blogging…”

        

Death by…Gamma-Ray Burst!


An artist’s impression of a very bad day…(Credit: ESO/A. Roquette).

Sure, we’ve all seen the movies with the impending death by asteroid or comet. You might have even heard of the havoc that can be wrecked by the Sun or an errant black hole, but have you ever heard of death by… gamma ray burst? Very much outside of public consciousness, this was but one of the more exotic ways humanity could have an official bad day that was outlined in Phil Plait’s outstanding Death from the Skies! But what are these exotic beasties, and just how likely are they? [Read more...]