Scientists can only see so far before they run into the edge of the universe. Will we ever know if anything lies beyond?
Astrophysicists have performed a powerful new analysis that places the most precise limits yet on the composition and evolution of the universe. With this analysis, dubbed Pantheon+, cosmologists find themselves at a crossroads.
Pantheon+ convincingly finds that the cosmos is composed of about two-thirds dark energy and one-third matter—mostly in the form of dark matter—and is expanding at an accelerating pace over the last several billion years. However, Pantheon+ also cements a major disagreement over the pace of that expansion that has yet to be solved.
By putting prevailing modern cosmological theories, known as the Standard Model of Cosmology, on even firmer evidentiary and statistical footing, Pantheon+ further closes the door on alternative frameworks accounting for dark energy and dark matter. Both are bedrocks of the Standard Model of Cosmology but have yet to be directly detected and rank among the model’s biggest mysteries. Following through on the results of Pantheon+, researchers can now pursue more precise observational tests and hone explanations for the ostensible cosmos.
The Universe gravitates so that normal matter and General Relativity alone can’t explain it. Here’s why dark matter beats modified gravity.
On Oct. 9, an unimaginably powerful influx of X-rays and gamma rays infiltrated our solar system. It was likely the result of a massive explosion that happened 2.4 billion light-years away from Earth, and it has left the science community stunned.
In the wake of the explosion, astrophysicists worldwide turned their telescopes toward the spectacular show, watching it unfold from a variety of cosmic vantage points — and as they vigilantly studied the event’s glimmering afterglow over the following week, they grew shocked by how utterly bright this gamma-ray burst seems to have been.
Eventually, the spectacle’s sheer intensity earned it a fitting (very millennial) name to accompany its robotic title of GRB221009A: B.O.A.T. — the “brightest of all time.”
This chaotic scene is where life’s ingredients are cast off into space. Cassiopeia A exploded in the 17th century, making it a fairly recent one.
In February 2016, scientists at the Laser Interferometer Gravitational-Wave Observatory (LIGO) announced the first-ever detection of gravitational waves (GWs). Originally predicted by Einstein’s Theory of General Relativity, these waves are ripples in spacetime that occur whenever massive objects (like black holes and neutron stars) merge. Since then, countless GW events have been detected by observatories across the globe – to the point where they have become an almost daily occurrence. This has allowed astronomers to gain insight into some of the most extreme objects in the Universe.
In a recent study, an international team of researchers led by Cardiff University observed a binary black hole system originally detected in 2020 by the Advanced LIGO, Virgo, and Kamioki Gravitational Wave Observatory (KAGRA). In the process, the team noticed a peculiar twisting motion (aka. a precession) in the orbits of the two colliding black holes that was 10 billion times faster than what was noted with other precessing objects. This is the first time a precession has been observed with binary black holes, which confirms yet another phenomenon predicted by General Relativity (GR).
Continue reading “Shortly Before They Collided, two Black Holes Tangled Spacetime up Into Knots” »
Keep an eye on the sky.
New models show that stars about to blow up in a supernovae begin exhibiting strange behaviors a few months in advance.
In a breathless press release, NASA emphasized that their detectors all over the planet picked up on this, including NASA’s Fermi Gamma-ray Space Telescope, the Neil Gehrels Swift Observatory, and the Wind spacecraft.
Gamma-ray bursts are some of the most powerful releases of energy in the universe. Their causes may vary slightly, but typically relate to black holes. Some may be caused when merging neutron stars create a black hole, or when a neutron star and a black hole merge. Because they are so energetic, even a gamma-ray burst that originates on the other side of the universe will often be detectable by astronomers on Earth.
On the morning of October 9, multiple space-based detectors picked up a powerful gamma-ray burst (GRB) passing through our solar system, sending astronomers around the world scrambling to train their telescopes on that part of the sky to collect vital data on the event and its afterglow. Dubbed GRB 221009A, astronomers say the gamma-ray burst is the most powerful yet recorded and likely could be the “birth cry” of a new black hole. The event was promptly published in the Astronomer’s Telegram, and observations are still ongoing.
“In our research group, we’ve been referring to this burst as the ‘BOAT,’ or Brightest Of All Time, because when you look at the thousands of bursts gamma-ray telescopes have been detecting since the 1990s, this one stands apart,” said Jillian Rastinejad, a graduate student at Northwestern University. Rastinejad led one of two independent teams using the Gemini South telescope in Chile to study the event’s afterglow.
“This burst is much closer than typical GRBs, which is exciting because it allows us to detect many details that otherwise would be too faint to see,” said Roberta Pillera, a graduate student at the Polytechnic University of Bari, Italy, and member of the Fermi Large Area Telescope (LAT) Collaboration. “But it’s also among the most energetic and luminous bursts ever seen regardless of distance, making it doubly exciting.”
Astronomers just detected what may be the most powerful flash of light ever seen.
The so-called gamma-ray burst, the most energetic type of electromagnetic explosion known to exist in the universe, was first spotted by telescopes Sunday (Oct. 9).
Gamma-ray bursts, which were discovered accidentally by U.S. military satellites in the 1960s, are likely produced when giant stars explode at the ends of their lives before collapsing into black holes, or when ultradense stellar remnants known as neutron stars collide. Within seconds, these explosions unleash as much energy as the sun will emit during its entire 10-billion-year lifetime.
