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New Insights Into Neutron Star Matter: Combining Heavy-Ion Experiments and Nuclear Theory – SciTechDaily

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Artist’s rendering showing the simulation of two merging neutron stars (left) and the emerging particle tracks that can be seen in a heavy-ion collision (right) that creates matter under similar conditions in the laboratory. Credit: Tim Dietrich, Arnaud Le Fevre, Kees Huyser; background: ESA/Hubble, Sloan Digital Sky Survey

Combining heavy-ion experiments, astrophysical observations, and nuclear theory.

When a massive star explodes in a supernova, if it isn’t completely destroyed, it will leave behind either a black hole or a <span class="glossaryLink" aria-describedby="tt" data-cmtooltip="

neutron star
A neutron star is the collapsed core of a large (between 10 and 29 solar masses) star. Neutron stars are the smallest and densest stars known to exist. Though neutron stars typically have a radius on the order of just 10 – 20 kilometers (6 – 12 miles), they can have masses of about 1.3 – 2.5 that of the Sun.

” data-gt-translate-attributes=”["attribute":"data-cmtooltip", "format":"html"]”>neutron star. These enigmatic cosmic objects are especially mysterious because of the crushing internal pressures resulting from neutron stars’ incredible density and the perplexing properties of the nuclear matter they are made of.

Now, an international team of researchers has for the first time combined data from heavy-ion experiments, gravitational wave measurements, and other astronomical observations using advanced theoretical modeling to more precisely constrain the properties of nuclear matter as it can be found in the interior of neutron stars. The results were published on June 8, 2022, in the journal Nature.

Neutron stars are formed when a giant star runs out of fuel and collapses. They are among the densest objects in the cosmos, with a single cube sized piece weighing 1 billion tons (1 trillion kg.)

Throughout the Universe, neutron stars are born in supernova explosions that mark the end of the life of massive stars. Sometimes neutron stars are bound in binary systems and will eventually collide with each other. These high-energy, astrophysical phenomena feature such extreme conditions that they produce most of the heavy elements, such as silver and gold. Consequently, neutron stars and their collisions are unique laboratories to study the properties of matter at densities far beyond the densities inside atomic nuclei. Heavy-ion collision experiments conducted with particle accelerators are a complementary way to produce and probe matter at high densities and under extreme conditions.

New insights into the fundamental interactions at play in nuclear matter

“Combining knowledge from nuclear theory, nuclear experiment, and astrophysical observations is essential to shedding light on the properties of neutron-rich matter over the entire density range probed in neutron stars,” said Sabrina Huth, Institute for Nuclear Physics at Technical University Darmstadt, who is one of the lead authors of the publication. Peter T. H. Pang, another lead author from the Institute for Gravitational and Subatomic Physics (GRASP), Utrecht University, added, “We find that constraints from collisions of gold ions with particle accelerators show a remarkable consistency with astrophysical observations even though they are obtained with completely different methods.”

Neutron Star Artist’s Depiction

Artist’s depiction of a neutron star. Credit: ESO / L. Calçada

Recent progress in multi-messenger astronomy allowed the international research team, involving researchers from Germany, the Netherlands, the US, and Sweden to gain new insights to the fundamental interactions at play in nuclear matter. In an interdisciplinary effort, the researchers included information obtained in heavy-ion collisions into a framework combining astronomical observations of electromagnetic signals, measurements of <span class="glossaryLink" aria-describedby="tt" data-cmtooltip="

gravitational waves
Gravitational waves are distortions or ripples in the fabric of space and time. They were first detected in 2015 by the Advanced LIGO detectors and are produced by catastrophic events such as colliding black holes, supernovae, or merging neutron stars.

” data-gt-translate-attributes=”["attribute":"data-cmtooltip", "format":"html"]”>gravitational waves, and high-performance astrophysics computations with theoretical nuclear physics calculations. Their systematic study combines all these individual disciplines for the first time, pointing to a higher pressure at intermediate densities in neutron stars.

Data of heavy-ion collisions included

The authors incorporated the information from gold-ion collision experiments performed at GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt as well as at Brookhaven National Laboratory and Lawrence Berkeley National Laboratory in the USA in their multi-step procedure that analyses constraints from nuclear theory and astrophysical observations, including neutron star mass measurements through radio observations, information from the Neutron Star Interior Composition Explorer (NICER) mission on the International Space Station (ISS), and multi-messenger observations of binary neutron star mergers.

The nuclear theorists Sabrina Huth and Achim Schwenk from Technical University Darmstadt and Ingo Tews from Los Alamos National Laboratory were key to translating the information gained in heavy-ion collisions to neutron star matter, which is needed to incorporate the astrophysics constraints.

Including data of heavy-ion collisions in the analyses has enabled additional constraints in the density region where nuclear theory and astrophysical observations are less sensitive. This has helped to provide a more complete understanding of dense matter. In the future, improved constraints from heavy-ion collisions can play an important role to bridge nuclear theory and astrophysical observations by providing complementary information. Especially experiments that probe higher densities while reducing the experimental uncertainties have great potential to provide new constraints for neutron star properties. New information on either side can easily be included in the framework to further improve the understanding of dense matter in the coming years.

Reference: “Constraining neutron-star matter with microscopic and macroscopic collisions” by Sabrina Huth, Peter T. H. Pang, Ingo Tews, Tim Dietrich, Arnaud Le Fèvre, Achim Schwenk, Wolfgang Trautmann, Kshitij Agarwal, Mattia Bulla, Michael W. Coughlin and Chris Van Den Broeck, 8 June 2022, Nature.
DOI: 10.1038/s41586-022-04750-w

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2022-06-29 | NDAQ:RKLB | Press Release | Rocket Lab USA Inc. – Stockhouse

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Rocket Lab USA, Inc. (Nasdaq: RKLB) (“Rocket Lab” or “the Company”), a leading launch and space systems company, today announced its Lunar Photon spacecraft has successfully completed the third of seven planned orbit raising maneuvers, bringing the CAPSTONE spacecraft closer to the Moon.

This press release features multimedia. View the full release here: https://www.businesswire.com/news/home/20220629005956/en/

The CAPSTONE satellite integrated onto Rocket Lab’s Lunar Photon spacecraft before launch on the Electron rocket. (Photo: Business Wire)

Owned and operated by Advanced Space on behalf of NASA, the Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) CubeSat will be the first spacecraft to test the Near Rectilinear Halo Orbit (NRHO) around the Moon. This is the same orbit intended for NASA’s Gateway, a multipurpose Moon-orbiting station that will provide essential support for long-term astronaut lunar missions as part of the Artemis program.

The orbit raising maneuvers come after Rocket Lab successfully launched CAPSTONE to an initial parking orbit on June 28 with an Electron rocket from Launch Complex 1 in New Zealand. With Electron’s role in the mission now complete, Lunar Photon has taken over the reins, providing power, communications and in-space transportation to CAPSTONE for the next five-day mission phase.

Over these days, Lunar Photon’s HyperCurie engine will perform a series of orbit raising maneuvers by igniting periodically to increase Photon’s velocity, stretching its orbit into a prominent ellipse around Earth. Six days after launch, HyperCurie will ignite one final time, accelerating Photon Lunar to 24,500 mph (39,500 km/h) and setting it on a ballistic lunar transfer. Within 20 minutes of this final burn, Photon will release CAPSTONE into space for the first leg of the CubeSat’s solo flight. CAPSTONE’s journey to NRHO is expected to take around four months from this point. Assisted by the Sun’s gravity, CAPSTONE will reach a distance of 963,000 miles from Earth – more than three times the distance between Earth and the Moon – before being pulled back towards the Earth-Moon system.

Rocket Lab founder and CEO Peter Beck said the launch of the CAPSTONE mission was the culmination of two and a half years of work and it pushed the Electron launch vehicle to the limit. “Electron lifted its heaviest payload yet at 300 kg – the combined mass of Lunar Photon and CAPSTONE. We pushed the Rutherford engines harder than we ever have before and deployed Lunar Photon and CAPSTONE exactly where they needed to go to begin the next mission phase. Now it’s Lunar Photon’s show and we’re immensely proud of its performance so far. We’re really pushing the boundaries of what’s possible for interplanetary smallsat missions with CAPSTONE and it’s exciting to think about the possibilities it opens up for more cost-effective missions to Mars, Venus and beyond.”

+ Images & Video Content

https://flic.kr/s/aHBqjzPrHL

+ About Rocket Lab

Founded in 2006, Rocket Lab is an end-to-end space company with an established track record of mission success. We deliver reliable launch services, satellite manufacture, spacecraft components, and on-orbit management solutions that make it faster, easier and more affordable to access space. Headquartered in Long Beach, California, Rocket Lab designs and manufactures the Electron small orbital launch vehicle and the Photon satellite platform and is developing the Neutron 8-ton payload class launch vehicle. Since its first orbital launch in January 2018, Rocket Lab’s Electron launch vehicle has become the second most frequently launched U.S. rocket annually and has delivered 147 satellites to orbit for private and public sector organizations, enabling operations in national security, scientific research, space debris mitigation, Earth observation, climate monitoring, and communications. Rocket Lab’s Photon spacecraft platform has been selected to support NASA missions to the Moon and Mars, as well as the first private commercial mission to Venus. Rocket Lab has three launch pads at two launch sites, including two launch pads at a private orbital launch site located in New Zealand and a second launch site in Virginia, USA which is expected to become operational in 2022. To learn more, visit www.rocketlabusa.com.

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Get hype for the first images from NASA’s James Webb Space Telescope – Yahoo Movies Canada

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Very soon, humanity will get to view the deepest images of the universe that have ever been captured. In two weeks, the $10 billion James Webb Space Telescope (JWST) — NASA’s super expensive, super powerful deep space optical imager — will release its first full-color images, and agency officials today suggested that they could just be the beginning.

“This is farther than humanity has ever looked before,” NASA Administrator Bill Nelson said during a media briefing Wednesday (he was calling in, as he had tested positive for COVID-19 the night before). “We’re only beginning to understand what Webb can and will do.”

NASA launched James Webb last December; ever since, it’s been conducting a specialized startup process that involves delicately tuning all 18 of its huge mirror segments. A few months ago, NASA shared a “selfie” marking the successful operations of the IR camera and primary mirrors. Earlier this month, the agency said the telescope’s first images will be ready for public debut at 10:30 AM ET on July 12.

One aspect of the universe that JWST will unveil is exoplanets, or planets outside our Solar System — specifically, their atmospheres. This is key to understanding whether there are other planets similar to ours in the universe, or if life can be found on planets under atmospheric conditions that differ from those found on Earth. And Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate, confirmed that images of an exoplanet’s atmospheric spectrum will be shared with the public on July 12.

Essentially, James Webb’s extraordinary capacity to capture the infrared spectrum means that it will be able to detect small molecules like carbon dioxide. This will enable scientists to actually examine whether and how atmospheric compositions shape the capacity for life to emerge and develop on a planet.

NASA officials also shared more good news: The agency’s estimates of the excess fuel capability of the telescope were spot on, and JWST will be able to capture images of space for around 20 years.

“Not only will those 20 years allow us to go deeper into history and time, but we will go deeper into science because we will have the opportunity to learn and grow and make new observations,” NASA deputy administrator Pam Melroy said.

JWST has not had an easy ride to deep space. The entire project came very close to not happening at all, Nelson said, after it started running out of money and Congress considered canceling it entirely. It also faced numerous delays due to technical issues. Then, when it reached space, it was promptly pinged by a micrometeoroid, an event that surely made every NASA official shudder.

But overall, “it’s been an amazing six months,” Webb project manager Bill Ochs confirmed.

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The Rings of Uranus and Neptune Could Help map Their Interiors – Universe Today

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Mapping the interior of the ice giants is difficult, to say the least. Not only are they far away and therefore harder to observe, but their constant ice cover makes it extremely hard to detect what lies underneath. So scientists must devise more ingenious ways to see what’s inside them. A team from the University of Idaho, Cal Tech, Reed College, and the University of Arizona think they might have come up with a way – to look at the structure of Neptunes’ and Uranus’ rings.

This isn’t the first technique scientists have used, though. Previous efforts have attempted to use the common technique of photometry to detect oscillations on the planet’s surface. Those oscillations can then be correlated to the density of particular parts of the planet’s interior. While the technique worked well for Jupiter, the photometry data we have of the ice giants so far have proved insufficient to determine the same density profiles. 

An alternative is using gravitational oscillations within the planet’s surface. In particular, there is a type of oscillation pattern known as a “normal mode.” This oscillation pattern happens when all parts of a system begin oscillating with the same sinusoidal frequency. And the gravitational effects of normal mode oscillations in the planet’s interior can be felt outside and reflected in the rings themselves.

[embedded content]
UT video discussing planetary rings in the solar system

It also isn’t the first time patterns in a planet’s rings have been used to calculate its internal density. Saturn has a better-understood ring system than Uranus or Neptune, the two ice giants with known ring systems. Scientists have been performing seismological analyses on the Saturnian ring system for years using data from Voyager and Cassini. The result is a better understanding of some of the normal modes of the planet’s interior and, therefore, an estimate of the makeup of the planet’s core and the rotation rate of the bulk of its material.

Neptune and Uranus each have a series of different rings, though they are not as well studied as Saturn’s. Some of those rings of which are corralled by shepherd moons. But according to the new paper, the same density reflections of resonance waves evident in Saturn’s rings are likely present in the ice giant’s ring systems as well.

What’s more, the inner shepherd moons themselves might be affected by the same resonances. Some of the moons can even create their own resonances, such as one known as a Lindblad resonance. More typically seen on the scale of galaxies, Lindblad resonances are known for driving spiral density waves, which cause the “arms” that can be seen in many spiral galaxies. But at a much smaller scale, the same effect happens on planetary ring systems, including Saturn’s, and most likely, Neptune’s and Uranus’.  

[embedded content]
UT video describing the Trident mission, which would return to Neptune.

The problem with using these resonances reflected in the rings is one that often faces science – there’s not enough data. So far, no probe has stayed long enough to map out the details needed to see the full scope of the ring system. The paper’s authors and plenty of other researchers suggest that it’s time to send a probe to the ice giants to effectively map the ring systems, moons, and myriad other recently discovered objects that are so hard to observe from the Earth. But for now, that mission is still on the drawing board, so we’ll have to wait to fully understand the interiors and ring system of these cold, barren worlds. At least when we finally do send a probe out that way, we’ll have the mathematical framework to help shed light on these dark places.

Learn More:
A’Hearn et al – Ring Seismology of the Ice Giants Uranus and Neptune
UT – The Rings of Neptune
UT – Which Planets Have Rings?
UT – How Many Rings Does Uranus Have?

Lead Image:
Artist impression of Uranus and its rings.
Credit – NRAO / AUI / NSF / S. Dagnello

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