When the Sun Dies, it Could Produce a Fantastic Ring in Space, Like This New Image From JWST

By Brian Koberlein - August 22, 2023 02:55 PM UTC | Stars
We recently got a new image of the famous Ring Nebula from JWST using its NIRCam instrument. This week we got an update taken with MIRI. The Ring Nebula is a perfect example of a planetary nebula, where a dying star throws its outer layers off into space. The new images reveal 20,000 individual clumps of dense molecular gas, each as massive as Earth. There is a narrow band of hydrocarbons in the ring, which surprised astronomers with its presence. The Ring Nebula is only 2,200 light-years from Earth, which makes it the ideal object to study, giving us clues about the future of our own Sun.
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A New Way to Measure the Expansion Rate of the Universe: Redshift Drift

By Brian Koberlein - August 19, 2023 01:37 PM UTC | Cosmology
Almost all the galaxies in the Universe are speeding away from us because of the Big Bang and the acceleration of dark energy. One technique to measure this expansion is redshift, seeing how light is reddened over time as its wavelength stretches out. But every observation astronomers can make is a snapshot, measuring the redshift now. But an intriguing idea is to measure how the redshift changes over time as a galaxy's movement accelerates. It's called "redshift drift" and requires an exact series of measurements over time.
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A New Simulation Reveals One Entire Stage of a Star's Life

By Brian Koberlein - August 18, 2023 02:39 PM UTC | Stars
Stars begin as giant clouds of gas and dust that pull together through mutual gravity into a dense protostar. At some point, the intense pressure and temperature cause fusion in the star's core, where lighter elements, like hydrogen, are fused into heavier elements, like helium. When the Sun runs out of one type of fuel, it shifts to the next type and begins the process again, with the heaviest stars reaching iron. A new simulation shows a portion of the interior of a star as it completes one of these stellar phases.
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We Might Be Able to Measure Dark Energy Through the Milky Way's Collision With Andromeda

By Brian Koberlein - August 17, 2023 01:34 PM UTC | Milky Way
The Milky Way and Andromeda are set to collide in a few billion years but are still over two million light-years apart. Cosmologically, this is right next door, but it could still be far enough to measure the effect of dark energy, which is pushing back on the galaxies coming together. According to a new study, the movement of the two galaxies towards each other could give an upper limit on the cosmological constant model of dark energy. Other merging pairs of galaxies could provide more data and help refine the measurements.
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New Horizons is So Far Away, it Can Measure the True Darkness of the Universe

By Brian Koberlein - August 16, 2023 02:29 PM UTC | Cosmology
NASA's New Horizons Spacecraft has completed its flybys of Pluto and Arrakoth and is now about 8 billion kilometers from Earth. Although astronomers are looking for another Kuiper Belt target, they can send it towards; the spacecraft is perfectly positioned to look at the Universe itself. At such a great distance, the spacecraft is beyond the dust that causes light pollution in the inner Solar System, darker than the darker skies on Earth. This unique vantage point will measure just how dark the Universe is.
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