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Nestars: Study suggests gravastars akin to nesting doll structure

Physicists have theorized the existence of new types of celestial objects that they name “nestars.”

These are gravitational condensate stars, or gravastars, nestled among other gravitational condensate stars, like a Russian matryoshka doll, or nesting doll.

This type of doll is distinguished by its hollow, round form and the ability to be split apart to reveal a sequence of increasingly smaller dolls nestled inside.

New nuclei can help shape our understanding of fundamental science on Earth and in the cosmos

In creating five new isotopes, an international research team working at the Facility for Rare Isotope Beams (FRIB) at Michigan State University has brought the stars closer to Earth.

The —known as thulium-182, thulium-183, ytterbium-186, ytterbium-187 and lutetium-190—are reported in the journal Physical Review Letters.

These represent the first batch of new isotopes made at FRIB, a user facility for the U.S. Department of Energy Office of Science, or DOE-SC, supporting the mission of the DOE-SC Office of Nuclear Physics. The new isotopes show that FRIB is nearing the creation of nuclear specimens that currently only exist when ultradense celestial bodies known as crash into each other.

A star like a Matryoshka doll: New theory for gravastars

The interior of black holes remains a conundrum for science. In 1916, German physicist Karl Schwarzschild outlined a solution to Albert Einstein’s equations of general relativity, in which the center of a black hole consists of a so-called singularity, a point at which space and time no longer exist. Here, the theory goes, all physical laws, including Einstein’s general theory of relativity, no longer apply; the principle of causality is suspended.

This constitutes a great nuisance for science—after all, it means that no information can escape from a black hole beyond the so-called event horizon. This could be a reason why Schwarzschild’s solution did not attract much attention outside the theoretical realm—that is, until the first candidate for a black hole was discovered in 1971, followed by the discovery of the black hole in the center of our Milky Way in the 2000s, and finally the first image of a black hole, captured by the Event Horizon Telescope Collaboration in 2019.

In 2001, Pawel Mazur and Emil Mottola proposed a different solution to Einstein’s field equations that led to objects that they called gravitational condensate stars, or gravastars. Contrary to black holes, gravastars have several advantages from a theoretical astrophysics perspective.

Staggering Structure in 19 Nearby Spiral Galaxies

The James Webb Space Telescope observed 19 nearby face-on spiral galaxies in near-and mid-infrared light as part of its contributions to the Physics at High Angular resolution in Nearby GalaxieS (PHANGS) program.

It’s oh-so-easy to be absolutely mesmerized by these spiral galaxies. Follow their clearly defined arms, which are brimming with stars, to their centers, where there may be old star clusters and – sometimes – active supermassive black holes. Only NASA’s James Webb Space Telescope can deliver highly detailed scenes of nearby galaxies in a combination of near-and mid-infrared light — and a set of these images was publicly released today.

These Webb images are part of a large, long-standing project, the Physics at High Angular resolution in Nearby GalaxieS (PHANGS) program, which is supported by more than 150 astronomers worldwide. Before Webb took these images, PHANGS was already brimming with data from NASA’s Hubble Space Telescope, the Very Large Telescope’s Multi-Unit Spectroscopic Explorer, and the Atacama Large Millimeter/submillimeter Array, including observations in ultraviolet, visible, and radio light. Webb’s near-and mid-infrared contributions have provided several new puzzle pieces.

Black Hole at the Center of a Galaxy in the Early Universe received Less Mass Influx than expected, astronomers find

With the upgraded GRAVITY-instrument at the Very Large Telescope Interferometer of the European Southern Observatory, a team of astronomers led by the Max Planck Institute for Extraterrestrial Physics has determined the mass of a black hole in a galaxy only 2 billion years after the Big Bang. With 300 million solar masses, the black hole is actually under-massive compared to the mass of its host galaxy. Researchers suspect what is happening here.

A paper on this work is published in the journal Nature.

In the more local universe, astronomers have observed tight relationships between the properties of galaxies and the mass of the supermassive black holes residing at their centers, suggesting that galaxies and black holes co-evolve. A crucial test would be to probe this relationship at early cosmic times, but for these far-away galaxies, traditional direct methods of measuring the black hole mass are either impossible or extremely difficult.

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