Water is made of hydrogen and oxygen: H2O. The H was formed during the Big Bang, but it took the first stars in the Universe to create the O, manufacturing it in their cores before they detonated as supernovae. In a new study, researchers suggest that those first supernovae released water into the Universe within the first 100-200 million years after the Big Bang, concentrating it into dense molecular clouds. Water needed for life was there, right at the beginning.
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The mass of the Milky Way's supermassive black hole, SgrA*, is roughly 4.3 million times the mass of the Sun, give or take a few hundred thousand solar masses. But a team of astronomers thinks they can dial that accuracy down to know with an error rate of a single solar mass. They propose to do this by measuring gravitational waves from SgrA* as brown dwarfs orbit it closely. These dwarfs act like natural probes mapping out the warped space around SgrA*.
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At the end of 2023, there were more than 5,000 satellites orbiting Earth, with 10s of 1000s more on the way. Although individual satellites might be invisible to the unaided eye, their collective light might already be causing a 10% brightness increase in the night sky. Large surveys like Vera Rubin will see frequent satellite trails obscuring important data. And the radio pollution is also increasing with communications satellites. What can be done to restore the sky?
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It's nearly impossible to identify individual stars billions of light years away. But thanks to gravitational lensing, astronomers have identified red giant stars in a distant galaxy.
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