When a dying star runs out of fuel and sheds its outer layers, its remaining core can become an approximately Earth-sized, extremely dense stellar remnant called a white dwarf. For a white dwarf that is not strongly rotating or magnetized, there is a well-known upper mass limit of about 1.4 times the mass of the sun, known as the Chandrasekhar limit.

As a carbon-oxygen white dwarf approaches this limit, its core can become dense enough to ignite carbon, potentially triggering a thermonuclear explosion known as a Type Ia supernova.

If the Chandrasekhar limit is fixed, the s...

An international collaboration led by a neurologist and experts in advanced genomics at Vanderbilt Health has coaxed one of the secrets of extreme longevity from a 194-year-old giant tortoise named Jonathan.

Jonathan’s secret involves entropy, the tendency of biological systems to become disordered over time.

One of the hallmarks of aging is mitochondrial dysfunction. It results from increasing entropy, or disorder, in “promoters,” the genetic on-and-off switches that regulate the efficiency of mitochondria, the energy-producing organelles in most animal cells. A reliable supply of cellular energy is essential for many biological processes.

Despite his many years, Jonathan somehow had avoide...

A Jupiter-sized world just 7.5 light-years away is cloudy, chemically complex and, it turns out, more like home than anyone expected. Using the James Webb Space Telescope, Brittany Miles, assistant astronomer at the University of Arizona’s Steward Observatory, led a team that spent 11 hours staring at WISE 0855, the coldest known brown dwarf, collecting a spectrum of its light every 15 minutes.

The result is the most detailed time-series portrait ever taken of this frigid world—and the first direct confirmation that water clouds on another body are changing thickness over time, just like we...

Oxidized lipids—fats structurally altered by enzymes, oxygen or free radicals—are double-edged swords that can both quell and ignite systemic inflammation, according to a new comprehensive review aimed at sharpening the overall understanding of an intricate class of highly reactive molecules.

Dr. Marco Di Gioia and Dr. Ivan Zanoni, two medical investigators from the divisions of immunology and gastroenterology at Harvard Medical School, explored this complex molecular universe by focusing on a class of compounds called oxidized phospholipids—oxPLs.

In their article published in Science Immunology, they explored why sharp differences in oxPL activity can have favorable or unfavorable biological outcomes...