Category Astronomy/Space

Astronomers uncover extremely hot and violent eruption from first ever near-infrared analysis of a recurrent nova outside of the Milky Way Galaxy. Using the Gemini South telescope, one half of the International Gemini Observatory, partly funded by the U.S. National Science Foundation and operated by NSF NOIRLab, and the Magellan Baade Telescope, astronomers have for the first time observed a recurring nova outside of the Milky Way in near-infrared light. The data revealed highly unusual chemical emissions as well as one of the hottest temperatures ever reported for a nova, both indicative of an extremely violent eruption.

Nova explosions occur in binary star systems in which a white dwarf — the dense remnant of a dead star — continually siphons stellar material from a nearby compan...

If there were such a thing as a photo album of the universe, it might include snapshots of pancake-like disks of gas and dust, swirling around newly formed stars across the Milky Way. Known as planet-forming disks, they are believed to be a short-lived feature around most, if not all, young stars, providing the raw materials for planets to form.

Most of these planetary nurseries are short-lived, typically lasting only about 10 million years—a fleeting existence by cosmic standards. Now, in a surprising find, researchers at the University of Arizona have discovered that disks can grace their host stars much longer than previously thought, provided the stars are small—one-tenth of the sun’s mass or less.

In a paper published in the Astrophysical Letters Journal, a research tea...

Water may have first formed 100–200 million years after the Big Bang, according to a modeling paper published in Nature Astronomy. The authors suggest that the formation of water may have occurred in the universe earlier than previously thought and may have been a key constituent of the first galaxies.

Water is crucial for life as we know it, and its components—hydrogen and oxygen—are known to have formed in different ways. Lighter chemical elements such as hydrogen, helium and lithium were forged in the Big Bang, but heavier elements, such as oxygen, are the result of nuclear reactions within stars or supernova explosions. As such, it is unclear when water began to form in the universe.

Researcher Daniel Whalen and colleagues utilized computer models of two supernovae—the...

Ultrahigh Energy Cosmic Rays are the highest-energy particles in the universe, whose energies are more than a million times what can be achieved by humans. But while the existence of UHECRs has been known for 60 years, researchers have not succeeded in formulating a satisfactory explanation for their origin that explains all the observations.

But a new theory introduced by New York University physicist Glennys Farrar provides a viable and testable explanation for how UHECRs are created.

“After six decades of effort, the origin of the mysterious highest-energy particles in the universe may finally have been identified,” says Farrar, a Collegiate Professor of Physics and Julius Silver, Rosalind S. Silver, and Enid Silver Winslow Professor at NYU...