Lifeboat Foundation

Last year, telescopes around the world registered the brightest cosmic explosion of all time. Astrophysicists can now explain what made it so dazzling.

Few cosmic explosions have attracted as much attention from space scientists as the one recorded on October 22 last year and aptly named the Brightest of All Time (BOAT). The event, produced by the collapse of a highly massive star and the subsequent birth of a black hole.

A black hole is a place in space where the gravitational field is so strong that not even light can escape it. Astronomers classify black holes into three categories by size: miniature, stellar, and supermassive black holes. Miniature black holes could have a mass smaller than our Sun and supermassive black holes could have a mass equivalent to billions of our Sun.

When black holes and other enormously massive, dense objects whirl around one another, they send out ripples in space and time called gravitational waves. These waves are one of the few ways we have to study the enigmatic cosmic giants that create them.

Astronomers have observed the high-frequency “chirps” of colliding black holes, but the ultra-low-frequency rumble of supermassive black holes orbiting one another has proven harder to detect. For decades, we have been observing pulsars, a type of star that pulses like a lighthouse, in search of the faint rippling of these waves.

Today, pulsar research collaborations around the world – including ours, the Parkes Pulsar Timing Array – announced their strongest evidence yet for the existence of these waves.

Elon Musk, the omnipotent ruler of the Twitterverse, has chimed in and has decreed that the actual physical universe is “possibly” twice as old as we think it is.

Make of that what you will.

Musk was responding to noted misinformation peddler and comedian Joe Rogan, who linked to a press release about a controversial new paper that indeed suggests the universe could be 26.7 billion years old, almost twice as the general consensus among scientists.

Astronomers have discovered a new type of stellar object that could change their understanding of extreme celestial bodies in the universe.

Initially, Curtin University doctoral student Tyrone O’Doherty spotted a spinning celestial space object in March 2018. The unfamiliar object released giant bursts of energy and beamed out radiation three times per hour.

In those moments, it became the brightest source of radio waves viewable from Earth through radio telescopes, acting like a celestial lighthouse.

York University and an international team of astrophysicists have made an ambitious attempt to simulate the formation of galaxies and cosmic large-scale structure throughout staggeringly large swaths of space.

First results of their MillenniumTNG project are published in a series of 10 articles in the journal Monthly Notices of the Royal Astronomical Society. The new calculations help to subject the standard cosmological model to precision tests and to unravel the full power of upcoming new cosmological observations, say the researchers including York Assistant Professor Rahul Kannan.

In recent decades, cosmologists have gotten used to the perplexing conjecture that the universe’s matter content is dominated by enigmatic dark matter and that an even stranger dark energy field that acts as some kind of anti-gravity to accelerate the expansion of today’s cosmos. Ordinary baryonic matter makes up less than five percent of the cosmic mix, but this source material forms the basis for the stars and planets of galaxies like our own Milky Way.

EMBARGO Wednesday 19 July 1,600 BST | 1,500 GMT | Thursday 20 July 100 AEST

Back when the Universe was still just a wee baby Universe, there wasn’t a lot going on chemically. There was hydrogen, with some helium, and a few traces of other things. Heavier elements didn’t arrive until stars had formed, lived, and died.

Imagine, therefore, the consternation of scientists when, using the James Webb Space Telescope to peer back into the distant reaches of the Universe, they discovered significant amounts of carbon dust, less than a billion years after the Big Bang.

“For decades Isaac Newton gave us this vision of a universe where space and time is fixed, and every clock across the universe ticks at exactly the same rate. Then Einstein shattered this vision by proposing that time is actually rubbery and relative,” says Geraint Lewis, an astrophysicist at the University of Sydney and lead author of the study. “Now we’ve shown that Einstein was, once again, correct.”

The Einsteinian concept of time running slower in the early universe arose in the late 1920s as astronomers were discovering cosmic expansion. Galaxies in the sky were found to be flying away from the Milky Way at high speed, swept along by the ceaselessly growing void—and the farther off they were, the faster they flew. This not only meant that the universe was once much smaller and denser—arising in a “big bang” from some compact, primordial point—but also that the most distant galaxies visible to us should be receding at close to the speed of light.

According to Einstein’s special and general theories of relativity, both circumstances alter the flow of time. As light from one of those far-distant galaxies travels from the heavier gravitational grip of the deep, dense early cosmos and across the continuously expanding universe, it must traverse increasingly greater expanses of space to reach Earth. Consequently, time becomes stretched in a phenomenon known as time dilation: a clock running 10 billion years ago would tick at a normal rate to an observer from that time, but from the perspective of someone today, it would appear to be ticking much slower.

“This gamma-ray burst was extremely bright. We expect to see one like this only every 10,000 years or so.”

A team of astronomers led by the University of Alabama in Huntsville has detected the brightest gamma-ray burst.

These bursts are thought to be among the most luminous explosions in the universe and created during the birth of black holes. GRBs generally last from less than a second to several minutes.

Continue reading “Three UAH researchers operating Gamma-ray Burst Monitor discover brightest gamma-ray burst ever detected” »

Teams of physicists worldwide have been trying to detect dark matter, an elusive type of matter that does not emit, absorb, or reflect light. Due to its lack of interactions with electromagnetic forces, this matter is very difficult to observe directly, thus most researchers are instead searching for signals originating from its interactions with other particles in its surroundings.

The PandaX experiment is a research effort dedicated to the search of dark matter using data collected by the Particle and Astrophysical xenon detector, situated at the China Jinping Underground Laboratory (CJPL) in Sichuan, in China. In a recent paper published in Physical Review Letters, the researchers involved in this large-scale experiment published the results of their most recent search for light dark matter (i.e., weakly interacting massive particles with masses below 1 GeV).

“Currently, strong constraints exist for heavy mass dark matter candidates derived from null results in direct detection experiments using xenon detectors,” Yue Meng, Qing Lin and Ning Zhou told Tech Xplore, on behalf of the PandaX collaboration. “However, traditional searches are not sensitive to light mass dark matter (less than GeV/c2) due to the detection energy threshold. Using an ionization-only signal (S2-only) to search for light mass dark matter can reduce the energy threshold from ~1 keV to 0.1 keV. Previous S2-only data analyses in xenon detectors were unable to model the background, which prevented effective and sensitive searches for light mass dark matter.”