“[A] team of European researchers decided to model an event that should be
relatively uncommon: the two black holes didn’t start out in a mutual orbit but
happened to pass close enough to gravitationally latch onto each other. … The
models that produced a chirp that best matched the GW190521
signal saw a single pass that drew the black holes closer, followed by a single
rapid curve into the collision.”
posted 11/28/2022 8:00pm ∞
“[T]he earliest image indicates that it was roughly 100,000 Kelvin, which
suggests we were looking at it just six hours after it exploded. The latest
lensed image shows that the debris had already cooled to 10,000 K over the
eight days between the two different images.”
posted 11/24/2022 8:00pm ∞
“Cosmic strings appear to be a generic prediction of our (admittedly fuzzy)
understanding of the early Universe. We may not know exactly what went down all
those billions of years ago, but we’re fairly certain that it involved phase
transitions and that those phase transitions should support the existence of
topological defects like cosmic strings.”
posted 10/16/2022 8:00pm ∞
“Bubbles of hydrogen-ripping galaxy light began to grow, carving holes in the
cold, quiet bulk of the intergalactic gas. Over a billion years, the bubbles
filled the cosmos and nearly every hydrogen atom was torn in two, leaving
protons and electrons to wander the Universe separately again.”
Katie Mack ,
How the first stars split the Universe apart
(BBC Science Focus October 10, 2022 )
posted 11/18/2022 8:00pm ∞
“[Betelgeuse’s] trademark pulsation has also stopped—hopefully
temporarily—perhaps because the interior convection cells ‘are sloshing around
like an imbalanced washing machine tub’ as the photosphere begins the slow
process of rebuilding itself.”
posted 10/7/2022 8:00pm ∞