The atmosphere of TOI 5205b has a lower concentration of heavy elements relative to hydrogen than gas giants in our own solar system, suggesting something different about its formation.
According to Einstein's General Relativity, for every black hole that exists within the Universe, there are only three properties that go into it that matter in any way: the black hole's total mass, the black hole's net electric charge, and the black hole's intrinsic angular momentum, and that's it. It doesn't matter what type of matter went into the black hole in order to form it; all that matters is its mass, charge, and angular momentum.
The closest supermassive black hole pair, in NGC 7727, was discovered in 2021. Just 89 million light-years away, these 154,000,000- and 6,300,000-solar-mass black holes are just 1,600 light-years apart. Approximately 0.1% of young quasars are expected to be doubles, with typical separations of ~10,000 light-years.
A bright star in a nearby galaxy has essentially vanished. Astronomers believe that it died and collapsed in on itself, transforming into the eerie cosmic phenomenon known as a black hole. "It used to be one of the brightest stars in the Andromeda galaxy," says Kishalay De, an astronomer with Columbia University and the Flatiron Institute. "Today, it is nowhere to be seen, even with the most sensitive telescopes."
This system is truly extraordinary. We're seeing the radio equivalent of a laser halfway across the universe. Fundamentally, masers and lasers are focused beams of light in the same frequency. In the realm of astrophysics, these can arise from clouds of dust being excited into a higher energy state from the light emitted by other sources, like stars and black holes.
A dead star 730 light years away appears to be forming a powerful structure around itself - and despite their best efforts, astronomers aren't sure how. The cosmic corpse, designated RXJ0528+2838, is an incredibly dense stellar remnant known as a white dwarf, with a Sun-like star orbiting around it. This binary arrangement isn't uncommon throughout the universe, but what is strange is the structure surrounding the former body: a highly energetic and luminescent cloud known as a nebula,
Supermassive black holes are mysterious bodies. Scientists aren't entirely sure how these beating hearts at the centers of most large galaxies formed. That includes Sagittarius A* (Sgr A*), the supermassive black hole at the center of our own Milky Way galaxy. Now a new preprint study is shedding light on Sagittarius A* by studying what happens as material falls toward the black hole.
The universe is exploding. Or parts of it are. The night sky may seem calm, even serene, but that masks events of a catastrophic and nearly unimaginable scale. Across the galaxy and even the cosmos itself, immense outbursts of energy occur that could easily vaporize our planet. Happily, space is vast, and the terrible distance between these events and us diminishes what we see to a faint glowusually.
Okay, first thing first: the universe is in fact expanding. We've known this for more than a century now, and it's the basis for modern cosmology. This idea is called the big bang modelwhich is an unfortunate name because it brings to mind a cosmos expanding like an explosion, with galaxies moving away from each other through space like shrapnel. But in fact space itself is expanding, and that's different.
Looking skyward fills us with wonder. Off-world, the Sun, planets, stars, and galaxies all await. Our Solar System encompasses our own cosmic backyard. Farther away, stars and star clusters abound within the Milky Way. Hundreds of billions of stars exist just within our home galaxy. Inside our Local Group, only Andromeda surpasses us in mass, size, and stars. More than 5 million light-years away, galaxies abound in groups and clusters.
Astronomers may have finally solved one of the weirdest mysteries of our night sky: why Betelgeuse, a massive star in the constellation Orion, seems to fade and brighten as if it were operated by a heavenly dimmer switch. Using the Hubble Space Telescope and ground-based observatories, scientists observed Betelgeuse for almost eight years and found that patterns in the star's light suggested the wake of another, unseen star was passing through its atmosphere.
