helium

A particle accelerator that slams electrons together here on Earth has achieved temperatures colder than those of outer space.Using the X-ray free-electron laser at the Department of Energy's SLAC National Accelerator Laboratory  –  part of an upgrade project to the Linac Coherent Light Source (LCLS), called LCLS II  – scientists chilled liquid helium to minus 456 degrees Fahrenheit (minus 271 degrees Celsius), or 2 kelvins.  That is just 2 kelvins above absolute zero, the coldest possible temperature at which all…

What's in a star? Well, if you're a highly evolved specimen nearing the end of its life named HD 222925, rather a heck of a lot, actually.Scientists have conducted an analysis of this dim object, and identified 65 separate elements. That's the most elements ever found in a single object outside the Solar System, and most of them are heavy elements from the bottom of the periodic table, rarely found in stars.  Since these elements can only form in extremely energetic events such as supernovae or neutron star mergers, via…

Study lead author Benni Birner of Scripps Institution of Oceanography at UC San Diego. Credit: Erik Jepsen/UC San Diego Scientists at Scripps Institution of Oceanography at UC San Diego used an unprecedented technique to detect that levels of helium are rising in the atmosphere, resolving an issue that has lingered among atmospheric chemists for decades.…