The Most Accurate View of the Milky Way

Gaia showed us that our galaxy's disk, the dark brown horizontal spanning from one side to the other, has a bit of a wave to it. Gaia also showed us that the Milky Way has more than two spiral arms and that they aren't as pronounced as we thought. Image Credit: ESA/Gaia/DPAC, Stefan Payne-Wardenaar CC BY-SA 3.0 IGO

We can judge the value of any scientific endeavour based on how much of our knowledge it overturns or transforms. By that metric, the ESA’s Gaia mission is a resounding success. The spacecraft gave us a precise, 3D map of our Milky Way galaxy and has forced us to abandon old ideas and replace them with compelling new ones.

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Webb and ALMA Team Up to Study Primeval Galaxy

The radio telescope array ALMA has pin-pointed the exact cosmic age of a distant JWST-identified galaxy, GHZ2/GLASS-z12, at 367 million years after the Big Bang. Image Credit: NASA/ESA/CSA/T. Treu, UCLA/NAOJ/T. Bakx, Nagoya U.

One of the most exciting developments in modern astronomy is how astronomers can now observe and study the earliest galaxies in the Universe. This is due to next-generation observatories like the James Webb Space Telescope (JWST), with its sophisticated suite of infrared instruments and spectrometers, and advances in interferometry – a technique that combines multiple sources of light to get a clearer picture of astronomical objects. Thanks to these observations, astronomers can learn more about how the earliest galaxies in the Universe evolved to become what we see today.

Using Webb and the Atacama Large Millimeter/submillimeter Array (ALMA), an international team led by researchers from the National Astronomical Observatory of Japan (NAOJ) successfully detected atomic transitions coming from galaxy GHZ2 (aka. GLASS-z12), located 13.4 billion light-years away. Their study not only set a new record for the farthest detection of these elements This is the first time such emissions have been detected in galaxies more than 13 billion light-years away and offers the first direct insights into the properties of the earliest galaxies in the Universe.

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Colliding Stars, Stellar Siphoning, and a now a “Blue Lurker.” This Star System has Seen it All

Triple star systems are more common than might be imagined – about one in ten of every Sun-like star is part of a system with two other stars. However, the dynamics of such a system are complex, and understanding the history of how they came to be even more so. Science took a step towards doing so with a recent paper by Emily Leiner from the Illinois Institute of Technology and her team.

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Recent Observations Challenge our Understanding of Giant Black Holes

Artist's impression of a white dwarf embedded in the disk of a giant black hole. Credit: NASA/Sonoma State University, Aurore Simonnet

Black holes are among the most mysterious and powerful objects in the Universe. These behemoths form when sufficiently massive stars reach the end of their life cycle and experience gravitational collapse, shedding their outer layers in a supernova. Their existence was illustrated by the work of German astronomer Karl Schwarzschild and Indian-American physicist Subrahmanyan Chandrasekhar as a consequence of Einstein’s Theory of General Relativity. By the 1970s, astronomers confirmed that supermassive black holes (SMBHs) reside at the center of massive galaxies and play a vital role in their evolution.

However, only in recent years were the first images of black holes acquired by the Event Horizon Telescope (EHT). These and other observations have revealed things about black holes that have challenged preconceived notions. In a recent study led by a team from MIT, astronomers observed oscillations that suggested an SMBH in a neighboring galaxy was consuming a white dwarf. But instead of pulling it apart, as astronomical models predict, their observations suggest the white dwarf was slowing down as it descended into the black hole – something astronomers have never seen before!

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The Gaia Mission’s Science Operations are Over

ESA’s Milky Way-mapper Gaia has completed the sky-scanning phase of its mission, racking up more than three trillion observations of about two billion stars and other objects over the last decade to revolutionise our view of our home galaxy and cosmic neighbourhood.

The ESA has announced that Gaia’s primary mission is coming to an end. The spacecraft’s fuel is running low, and the sky-scanning phase of its mission is over. The ground-breaking mission has taken more than three trillion observations of two billion objects, mostly stars.

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About a Third of Supermassive Black Holes are Hiding

A supermassive black hole surrounded by a torus of gas and dust is depicted in four different wavelengths of light in this artist’s concept. Visible light (top right) and low-energy X-rays (bottom left) are blocked by the torus; infrared (top left) is scattered and reemitted; and some high energy X-rays (bottom right) can penetrate the torus. Image Credit: NASA/JPL-Caltech

Supermassive black holes can have trillions of times more mass than the Sun, only exist in specific locations, and could number in the trillions. How can objects like that be hiding? They’re shielded from our view by thick columns of gas and dust.

However, astronomers are developing a way to find them: by looking for donuts that glow in the infrared.

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The First Supernovae Flooded the Early Universe With Water

This artist’s impression shows CR7 a very distant galaxy discovered using ESO’s Very Large Telescope. Credit: ESO/M. Kornmesser

Water is the essence of life. Every living thing on Earth contains water within it. The Earth is rich with life because it is rich with water. This fundamental connection between water and life is partly due to water’s extraordinary properties, but part of it is due to the fact that water is one of the most abundant molecules in the Universe. Made from one part oxygen and two parts hydrogen, its structure is simple and strong. The hydrogen comes from the primordial fire of the Big Bang and is by far the most common element. Oxygen is created in the cores of large stars, along with carbon and nitrogen, as part of the CNO fusion cycle.

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Astronomers See Flares Coming from the Milky Way’s Supermassive Black Hole

This artist’s conception of the mid-IR flare in Sgr A* captures the variability, or changing intensity, of the flare as the black hole’s magnetic field lines bunch together. This bunching results in magnetic reconnection, which produces particles and energy that spiral along the magnetic field lines until they cool and release their energy, spiking the intensity of the flare. Credit: CfA/Melissa Weiss

There’s plenty of action at the center of the galaxy, where a supermassive black hole (SMBH) known as Sagittarius A* (Sgr A*) literally holds the galaxy together. Part of that action is the creation of gigantic flares from Sgr A*, which can give off energy equivalent to 10 times the Sun’s annual energy output. However, scientists have been missing a key feature of these flares for decades – what they look like in the mid-infrared range. But now, a team led by researchers at Harvard’s Center for Astrophysics and the Max Planck Institute for Radio Astronomy has published a paper that details what a flare looks like in those frequencies for the first time.

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Earth’s Temporary Moon Might Have Come from THE Moon

The orbit of Near Earth Asteroid 2024 PT5. This asteroid may have once been part of the Moon. Courtesy NASA.
The orbit of Near Earth Asteroid 2024 PT5. This asteroid may have once been part of the Moon. Courtesy NASA.

A tiny asteroid loitering in a near-Earth orbit for a few months last year may have an intriguing origin on our Moon. Its characteristics led scientists to ask: is it a chip off the old lunar block, making a pass by Earth for a visit?

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