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Surface Helium Detonation Spells End for White Dwarf

A hybrid type Ia supernova with an early flash triggered by helium-shell detonation. Nature, 2017; 550 (7674): 80 DOI: 10.1038/nature23908

A hybrid type Ia supernova with an early flash triggered by helium-shell detonation. Nature, 2017; 550 (7674): 80 DOI: 10.1038/nature23908

Researchers have found evidence that the brightest stellar explosions in our Universe could be triggered by helium nuclear detonation near the surface of a white dwarf star. The most famous supernovae are the result of a massive star exploding, but a white dwarf, the remnant of an intermediate mass star like our Sun, can also explode. This can occur if the white dwarf is part of a binary star system. The white dwarf accretes material from the companion star, then at some point, it might explode as a type Ia supernova.

Because of the uniform and extremely high brightness (about 5 billion times brighter than the Sun) of type Ia supernovae, they are often ...

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The Super-Earth that came Home for Dinner

An artist's illustration of a possible ninth planet in our solar system, hovering at the edge of our solar system. Neptune's orbit is shown as a bright ring around the Sun. Credit: ESO/Tom Ruen/nagualdesign

An artist’s illustration of a possible ninth planet in our solar system, hovering at the edge of our solar system. Neptune’s orbit is shown as a bright ring around the Sun. Credit: ESO/Tom Ruen/nagualdesign

It might be lingering on the icy outer edges of our solar system, stretching out the orbits of distant bodies, perhaps even tilting the entire solar system to one side. It is a possible “Planet Nine” – a world perhaps 10 times the mass of Earth and 20 times farther from the sun than Neptune. The signs so far are indirect, mainly its gravitational footprints, but that adds up to a compelling case nonetheless. One of its most dedicated trackers, in fact, says it is now harder to imagine our solar system without a Planet Nine than with one.

“There are now five different lines of observati...

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Gut Bacteria Metabolism may factor into Hypertension

Ridlon and endocrinologist David Morris explain the mechanism that links gut bacteria to hypertension in humans.

Ridlon and endocrinologist David Morris explain the mechanism that links gut bacteria to hypertension in humans.

1 in 3 American adults suffers from high blood pressure, or hypertension. The disease can be passed down in families, and certain lifestyle factors such as smoking, high-sodium diets, and stress can increase the risk. In recent years, scientists have discovered that certain gut bacteria may contribute to hypertension, as well. In a few studies, when gut bacteria were killed off with antibiotics, patients with hypertension saw a drop in blood pressure. And when gut bacteria were transplanted from hypertensive people into normal mice, they developed high blood pressure...

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Superconductivity found in Thin films of Titanium Oxide

This is a schematic representation of Ti4O7 (a) and ?-Ti3O5 (b). Credit: Scientific Reports

This is a schematic representation of Ti4O7 (a) and γ-Ti3O5 (b). Credit: Scientific Reports

Many of us are familiar with titanium dioxide (TiO2), a whitener commonly used in sunscreens and paints such as the white lines seen on tennis courts. Less well known are other higher titanium oxides – those with a higher number of titanium and oxygen atoms than TiO – that are now the subject of intensifying research due to their potential use in next-generation electronic devices. Now, researchers at Tokyo Tech have reported superconductivity in two kinds of higher titanium oxides prepared in the form of ultrathin films. With a thickness of around 120nm, these materials reveal properties that are only just beginning to be explored.

“We succeeded in growing thin films of Ti4O7 and γ-Ti3O5 for the f...

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