white dwarf tagged posts

Student astronomer discovers ‘Rosetta Stone’ for mysterious cosmic signals

Left: Accreting white dwarf illustration, created by Carl Knox (OzGrav, Swinburne University of Technology) and Joshua Preston Pritchard (CSIRO). Top right: Lead author Kovi Rose from the University of Sydney in front of illustration of the white dwarf binary. ©  Carl Knox Bottom Left: CSIRO ’s ASKAP radio telescope on Wajarri Yamaji Country. Credit: Alex Cherney.

An international team led by astronomers at the University of Sydney has uncovered the clearest evidence yet for the origin of an unusual class of cosmic signals. In doing so, they have identified a rare stellar system that is providing scientists with a natural laboratory to study extreme physics.

Using CSIRO’s ASKAP radio telescope, the team discovered a small, dense star, called a white dwarf, shredding material ...

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A white dwarf’s cosmic feeding frenzy revealed by NASA

This artist’s concept depicts a smaller white dwarf star pulling material from a larger star, right, into an accretion disk. Earlier this year, scientists used NASA’s IXPE (Imaging X-ray Polarization Explorer) to study a white dwarf star and its X-ray polarization.
MIT/Jose-Luis Olivares

Using NASA’s IXPE, astronomers captured an unprecedented view of a white dwarf star actively feeding on material from a companion. The data revealed giant columns of ultra-hot gas shaped by the star’s magnetic field and glowing in intense X-rays. These features are far too small to image directly, but X-ray polarization allowed scientists to map them with surprising precision. The results open new doors for understanding extreme binary star systems.

Scientists have, for the first time, used N...

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Icy planetesimal with high nitrogen and water content discovered in white dwarf’s atmosphere

Cosmic crime scene: White dwarf found devouring Pluto-like icy world
Artist’s impression of white dwarf WD 1647+375 accreting icy planetary fragments from a pluto-like world, creating the chemical signature idenfitifed in this study. Credit: Snehalata Sahu / University of Warwick

University of Warwick astronomers have uncovered the chemical fingerprint of a frozen, water-rich planetary fragment being consumed by a white dwarf star outside our solar system.

In our solar system, it is thought that comets and icy planetesimals (small solid objects in space) were responsible for delivering water to Earth. The existence of these icy objects is a requirement for the development of life on other worlds, but it is incredibly difficult to identify them outside our solar system as icy objects are small, faint and require chemical analysis.

In a study publis...

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A New Class of Cosmic X-ray Sources discovered

An international team of astronomers, led by researchers from the Astronomical Observatory of the University of Warsaw, have identified a new class of cosmic X-ray sources. The findings have been published in The Astrophysical Journal Letters.

Most people encounter X-rays during medical visits where they are used to create images of bones or diagnose lung conditions. These X-rays are generated using artificial sources.

However, not everyone knows that celestial objects can also emit X-ray radiation. “Some cosmic phenomena produce X-rays naturally,” explains Dr. Przemek Mróz, the lead author of the study. “For example, X-rays may be produced by a hot gas falling onto compact objects like white dwarfs, neutron stars, or black holes...

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