Bizarre star could host a neutron star in its core

Astronomers spot best candidate for a Thorne-Zytkow object, a hybrid star proposed almost 40 years ago.

Astronomers say that they have discovered the first example of a long-sought cosmic oddity: a bloated, dying star with a surprise in its core — an ultradense neutron star.

Such entities, known as Thorne-Zytkow objects, are theoretically possible but would alter scientists’ understanding of how stars can be powered. Since Thorne-Zytkow objects were first proposed in 19751, researchers have occasionally offered up candidates, but none have been confirmed.

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CrazyNeutrino said:

Bizarre star could host a neutron star in its core

Astronomers spot best candidate for a Thorne-Zytkow object, a hybrid star proposed almost 40 years ago.

Astronomers say that they have discovered the first example of a long-sought cosmic oddity: a bloated, dying star with a surprise in its core — an ultradense neutron star.

Such entities, known as Thorne-Zytkow objects, are theoretically possible but would alter scientists’ understanding of how stars can be powered. Since Thorne-Zytkow objects were first proposed in 19751, researchers have occasionally offered up candidates, but none have been confirmed.

more…

Shouldn’t you have said; won’t be first proposed until 19751.

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Shouldn’t you have said; won’t be first proposed until 19751.
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thanks for pointing that out, seems the correct date is 1977

Thorne–Żytkow object

A Thorne–Żytkow object or TŻO is a hypothetical type of star wherein a red giant or supergiant contains a neutron star at its core. Such objects were hypothesized by Kip Thorne and Anna Żytkow in 1977. Although some objects have been suggested as candidates, none has been confirmed

Formation

A Thorne–Żytkow object is formed when a neutron star collides with a star, typically a red giant or supergiant. The colliding objects can simply be wandering stars. This is only likely to occur in extremely crowded globular clusters. Alternatively, the neutron star could form in a binary system. Because no supernova is perfectly symmetric, the neutron star will be left with a small velocity relative to its original orbit. This kick may cause its new orbit to intersect with its companion, or, if its companion is a main-sequence star, be engulfed by its companion when it evolves into a red giant.

Once the neutron star enters the red giant, drag between the neutron star and the outer, diffuse layers of the red giant causes the binary star system’s orbit to decay, and the neutron star and core of the red giant spiral inward toward one another. Depending on their initial separation, this process may take hundreds of years. When the two finally collide, the neutron star and red giant core will merge. If their combined mass exceeds the Tolman-Oppenheimer-Volkoff limit then the two will collapse into a black hole, resulting in a supernova that disperses the outer layers of the star. Otherwise, the two will coalesce into a single neutron star.