Astronomers say S5-HVs1 ventured close to supermassive black hole before being ejected.
Category: cosmology – Page 333
Nuclear Fantasies
Posted in cosmology
Neutron stars cannot exist.
“The sky was clear—remarkably clear—and the twinkling of all the stars seemed to be but throbs of one body, timed by a common pulse.” —Thomas Hardy.
On June 13, 2012 NASA launched the Nuclear Spectroscopic Telescope Array (NuSTAR) on a mission to study X-rays in what are thought to be the remnants of supernova explosions, called pulsars. NuStar joins other X-ray space telescopes like Chandra and XMM-Newton, except that it is capable of focusing X-rays to a sharp point, enabling it to “see” energies up to 79,000 electron-volts. That capability makes it more than 100 times more powerful than the other observatories.
How to Peer Through a Wormhole
Posted in cosmology
Theoretically, the universe may be riddled with tunnels through space and time. Two scientists have now proposed a way to detect the existence of a cosmic escape hatch.
Stars explode. But how?
A recent press release asks, “What happens when a star explodes?” The answer, not surprisingly, is, “…the same thing that happens when gas explodes here on Earth.”
The Electric Universe agrees with modern physics: a supernova is an exploding star. However, there is much more to the story that involves plasma. Electricity flowing through plasma creates regions of charge separation isolated by double layers. Could charge separation be the foundation for supernovae?
NASA recently detected a massive thermonuclear explosion coming from outer space.
The culprit seems to be a distant pulsar, the space agency reports, which is the stellar remains of a star that blew up in a supernova but was too small to form a black hole. NASA spotted the burst because it sent out an intense beam of x-rays that got picked up by the agency’s orbital observatory NICER.
All in all, it serves as a potent reminder: space is an extremely dangerous, extremely metal place.
There’s a hole in the story of how our universe came to be. First, the universe inflated rapidly, like a balloon. Then, everything went boom.
But how those two periods are connected has eluded physicists. Now, a new study suggests a way to link the two epochs.
Most people think of space as a flat sheet: You travel in one direction, and you end up far from your starting point. But a new paper suggests that the universe may in fact be spherical: If you travel far enough in the same direction, you’d end up back where you started.
Based on Einstein’s theory of relativity, space can bend into different shapes, so scientists assume the universe must be either open, flat, or closed. Flat is the easiest shape to understand: it is how we experience space in our everyday lives, as a plane in which a beam of light would extend off into infinity. An open universe would be saddle-shaped, with a beam of light bending across the curvature. And a closed universe would be a sphere, with a beam of light eventually looping back around it to meet its origin.
In order to tell which shape our universe is, scientists can look at a phenomenon called the cosmic microwave background (CMB). This is the electromagnetic radiation which remains from the Big Bang, also called “relic radiation.” It fills all of space and can be detected with a sufficiently powerful radio telescope.
The XENON experiment recently made a breakthrough in their hunt for dark matter, observing the most rare decay process in the Universe that involves neutrinos.
Wielding state-of-the-art technologies and techniques, a team of Clemson University astrophysicists has added a novel approach to quantifying one of the most fundamental laws of the universe.
In a paper published Friday, Nov. 8, in The Astrophysical Journal, Clemson scientists Marco Ajello, Abhishek Desai, Lea Marcotulli and Dieter Hartmann have collaborated with six other scientists around the world to devise a new measurement of the Hubble Constant, the unit of measure used to describe the rate of expansion of the universe.
“Cosmology is about understanding the evolution of our universe—how it evolved in the past, what it is doing now and what will happen in the future,” said Ajello, an associate professor in the College of Science’s department of physics and astronomy. “Our knowledge rests on a number of parameters—including the Hubble Constant—that we strive to measure as precisely as possible. In this paper, our team analyzed data obtained from both orbiting and ground-based telescopes to come up with one of the newest measurements yet of how quickly the universe is expanding.”