Members Can Post Anonymously On This Site
The Marshall Star for October 16, 2024
-
Similar Topics
-
By NASA
3 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video
A 3D simulation showing the evolution of turbulent flows in the upper layers of the Sun. The more saturated and bright reds represent the most vigorous upward or downward twisting motions. Clear areas represent areas where there is only relatively slow up-flows, with very little twisting.NASA/Irina Kitiashvili and Timothy A. Sandstrom NASA supercomputers are shedding light on what causes some of the Sun’s most complex behaviors. Using data from the suite of active Sun-watching spacecraft currently observing the star at the heart of our solar system, researchers can explore solar dynamics like never before.
The animation shows the strength of the turbulent motions of the Sun’s inner layers as materials twist into its atmosphere, resembling a roiling pot of boiling water or a flurry of schooling fish sending material bubbling up to the surface or diving it further down below.
“Our simulations use what we call a realistic approach, which means we include as much as we know to-date about solar plasma to reproduce different phenomena observed with NASA space missions,” said Irina Kitiashvili, a scientist at NASA’s Ames Research Center in California’s Silicon Valley who helped lead the study.
Using modern computational capabilities, the team was able, for the first time to reproduce the fine structures of the subsurface layer observed with NASA’s Solar Dynamics Observatory.
“Right now, we don’t have the computational capabilities to create realistic global models of the entire Sun due to the complexity,” said Kitiashvili. “Therefore, we create models of smaller areas or layers, which can show us structures of the solar surface and atmosphere – like shock waves or tornado-like features measuring only a few miles in size; that’s much finer detail than any one spacecraft can resolve.”
Scientists seek to better understand the Sun and what phenomena drive the patterns of its activity. The connection and interactions between the Sun and Earth drive the seasons, ocean currents, weather, climate, radiation belts, auroras and many other phenomena. Space weather predictions are critical for exploration of space, supporting the spacecraft and astronauts of NASA’s Artemis campaign. Surveying this space environment is a vital part of understanding and mitigating astronaut exposure to space radiation and keeping our spacecraft and instruments safe.
This has been a big year for our special star, studded with events like the annular eclipse, a total eclipse, and the Sun reaching its solar maximum period. In December 2024, NASA’s Parker Solar Probe mission – which is helping researchers to understand space weather right at the source – will make its closest-ever approach to the Sun and beat its own record of being the closest human-made object to reach the Sun.
The Sun keeps surprising us. We are looking forward to seeing what kind of exciting events will be organized by the Sun."
Irina Kitiashvili
NASA Scientist
“The Sun keeps surprising us,” said Kitiashvili. “We are looking forward to seeing what kind of exciting events will be organized by the Sun.”
These simulations were run on the Pleaides supercomputer at the NASA Advanced Supercomputing facility at NASA Ames over several weeks of runtime, generating terabytes of data.
NASA is showcasing 29 of the agency’s computational achievements at SC24, the international supercomputing conference, Nov. 17-22, 2023, in Atlanta, Georgia. For more technical information, visit:
https://www.nas.nasa.gov/sc24
For news media: Members of the news media interested in covering this topic should reach out to the NASA Ames newsroom.
Share
Details
Last Updated Nov 21, 2024 Related Terms
General Ames Research Center Heliophysics Solar Dynamics Observatory (SDO) Sunspots The Sun Explore More
2 min read Weld-ASSIST: Weldability Assessment for In-Space Conditions using a Digital Twin
Article 5 hours ago 5 min read NASA’s Chandra, Hubble Tune Into ‘Flame-Throwing’ Guitar Nebula
Article 23 hours ago 4 min read Protected: 2024 Blue Marble Awards
Article 24 hours ago Keep Exploring Discover More Topics From NASA
Parker Solar Probe
On a mission to “touch the Sun,” NASA’s Parker Solar Probe became the first spacecraft to fly through the corona…
Solar Storms and Flares
Solar storms and flares are eruptions from the Sun that can affect us here on Earth.
Solar System
Track the Solar Cycle with Sunspots
Participate in sunspot-counting activities using NASA telescopes or your own.
View the full article
-
By NASA
Hubble Space Telescope Home NASA’s Hubble Finds… Hubble Space Telescope Hubble Home Overview About Hubble The History of Hubble Hubble Timeline Why Have a Telescope in Space? Hubble by the Numbers At the Museum FAQs Impact & Benefits Hubble’s Impact & Benefits Science Impacts Cultural Impact Technology Benefits Impact on Human Spaceflight Astro Community Impacts Science Hubble Science Science Themes Science Highlights Science Behind Discoveries Hubble’s Partners in Science Universe Uncovered Explore the Night Sky Observatory Hubble Observatory Hubble Design Mission Operations Missions to Hubble Hubble vs Webb Team Hubble Team Career Aspirations Hubble Astronauts News Hubble News Hubble News Archive Social Media Media Resources Multimedia Multimedia Images Videos Sonifications Podcasts E-books Lithographs Fact Sheets Glossary Posters Hubble on the NASA App More Online Activities 5 Min Read NASA’s Hubble Finds Sizzling Details About Young Star FU Orionis
An artist’s concept of the early stages of the young star FU Orionis (FU Ori) outburst, surrounded by a disk of material. Credits:
NASA-JPL, Caltech In 1936, astronomers saw a puzzling event in the constellation Orion: the young star FU Orionis (FU Ori) became a hundred times brighter in a matter of months. At its peak, FU Ori was intrinsically 100 times brighter than our Sun. Unlike an exploding star though, it has declined in luminosity only languidly since then.
Now, a team of astronomers has wielded NASA’s Hubble Space Telescope‘s ultraviolet capabilities to learn more about the interaction between FU Ori’s stellar surface and the accretion disk that has been dumping gas onto the growing star for nearly 90 years. They find that the inner disk touching the star is extraordinarily hot — which challenges conventional wisdom.
The observations were made with the telescope’s COS (Cosmic Origins Spectrograph) and STIS (Space Telescope Imaging Spectrograph) instruments. The data includes the first far-ultraviolet and new near-ultraviolet spectra of FU Ori.
“We were hoping to validate the hottest part of the accretion disk model, to determine its maximum temperature, by measuring closer to the inner edge of the accretion disk than ever before,” said Lynne Hillenbrand of Caltech in Pasadena, California, and a co-author of the paper. “I think there was some hope that we would see something extra, like the interface between the star and its disk, but we were certainly not expecting it. The fact we saw so much extra — it was much brighter in the ultraviolet than we predicted — that was the big surprise.”
A Better Understanding of Stellar Accretion
Originally deemed to be a unique case among stars, FU Ori exemplifies a class of young, eruptive stars that undergo dramatic changes in brightness. These objects are a subset of classical T Tauri stars, which are newly forming stars that are building up by accreting material from their disk and the surrounding nebula. In classical T Tauri stars, the disk does not touch the star directly because it is restricted by the outward pressure of the star’s magnetic field.
The accretion disks around FU Ori objects, however, are susceptible to instabilities due to their enormous mass relative to the central star, interactions with a binary companion, or infalling material. Such instability means the mass accretion rate can change dramatically. The increased pace disrupts the delicate balance between the stellar magnetic field and the inner edge of the disk, leading to material moving closer in and eventually touching the star’s surface.
This is an artist’s concept of the early stages of the young star FU Orionis (FU Ori) outburst, surrounded by a disk of material. A team of astronomers has used the Hubble Space Telescope’s ultraviolet capabilities to learn more about the interaction between FU Ori’s stellar surface and the accretion disk that has been dumping gas onto the growing star for nearly 90 years. They found that the inner disk, touching the star, is much hotter than expected—16,000 kelvins—nearly three times our Sun’s surface temperature. That sizzling temperature is nearly twice as hot as previously believed. NASA-JPL, Caltech
Download this image
The enhanced infall rate and proximity of the accretion disk to the star make FU Ori objects much brighter than a typical T Tauri star. In fact, during an outburst, the star itself is outshined by the disk. Furthermore, the disk material is orbiting rapidly as it approaches the star, much faster than the rotation rate of the stellar surface. This means that there should be a region where the disk impacts the star and the material slows down and heats up significantly.
“The Hubble data indicates a much hotter impact region than models have previously predicted,” said Adolfo Carvalho of Caltech and lead author of the study. “In FU Ori, the temperature is 16,000 kelvins [nearly three times our Sun’s surface temperature]. That sizzling temperature is almost twice the amount prior models have calculated. It challenges and encourages us to think of how such a jump in temperature can be explained.”
To address the significant difference in temperature between past models and the recent Hubble observations, the team offers a revised interpretation of the geometry within FU Ori’s inner region: The accretion disk’s material approaches the star and once it reaches the stellar surface, a hot shock is produced, which emits a lot of ultraviolet light.
Planet Survival Around FU Ori
Understanding the mechanisms of FU Ori’s rapid accretion process relates more broadly to ideas of planet formation and survival.
“Our revised model based on the Hubble data is not strictly bad news for planet evolution, it’s sort of a mixed bag,” explained Carvalho. “If the planet is far out in the disk as it’s forming, outbursts from an FU Ori object should influence what kind of chemicals the planet will ultimately inherit. But if a forming planet is very close to the star, then it’s a slightly different story. Within a couple outbursts, any planets that are forming very close to the star can rapidly move inward and eventually merge with it. You could lose, or at least completely fry, rocky planets forming close to such a star.”
Additional work with the Hubble UV observations is in progress. The team is carefully analyzing the various spectral emission lines from multiple elements present in the COS spectrum. This should provide further clues on FU Ori’s environment, such as the kinematics of inflowing and outflowing gas within the inner region.
“A lot of these young stars are spectroscopically very rich at far ultraviolet wavelengths,” reflected Hillenbrand. “A combination of Hubble, its size and wavelength coverage, as well as FU Ori’s fortunate circumstances, let us see further down into the engine of this fascinating star-type than ever before.”
These findings have been published in The Astrophysical Journal Letters.
The observations were taken as part of General Observer program 17176.
The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.
Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubble Media Contacts:
Claire Andreoli (claire.andreoli@nasa.gov)
NASA’s Goddard Space Flight Center, Greenbelt, MD
Abigail Major, Ray Villard
Space Telescope Science Institute, Baltimore, MD
Share
Details
Last Updated Nov 21, 2024 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
Astrophysics Astrophysics Division Goddard Space Flight Center Hubble Space Telescope Stars Keep Exploring Discover More Topics From Hubble
Hubble Space Telescope
Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.
Exploring the Birth of Stars
Hubble’s Night Sky Challenge
Hubble Focus: The Lives of Stars
This e-book highlights the mission’s recent discoveries and observations related to the birth, evolution, and death of stars.
View the full article
-
By NASA
1 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Back to ESI Home
Computational Materials Engineering for Lunar Metals Welding
Azadeh Haghighi
University of Illinois, Chicago
Weld-ASSIST: Weldability Assessment for In-Space Conditions using a Digital Twin Wei Li
University of Texas at Dallas
Integrated Computational Materials Modelling Framework for Investigating the Process-Structure-Property Linkage of the Lunar Metal Welding with Internal Defects Passive Lunar Dust Control through Advanced Materials and Surface Engineering
SungWoo Nam
University of California, Irvine
Deformable Crumpled Nano-ball Coatings with Adaptable Adhesion and Mechanical Energy Absorption for Lunar Dust Mitigation Chih-Hao Chang
University of Texas at Austin
Engineering the Adhesion Mechanisms of Hierarchical Dust-Mitigating Nanostructures Lei Zhai
University of Central Florida
Studying Passive Dust Mitigation on Anisotropic Structured Surface Min Zou
University of Arkansas, Fayetteville
Developing High-Performance Bioinspired Surface Textures for Repelling Lunar Dust Keep Exploring Discover More Topics From STRG
Space Technology Mission Directorate
STMD Solicitations and Opportunities
Space Technology Research Grants
About STRG
View the full article
-
By NASA
This content is password protected. To view it please enter your password below:
Password:
View the full article
-
By NASA
Anthocyanins protect seeds in space
After exposure to space outside the International Space Station, purple-pigmented rice seeds rich in anthocyanin had higher germination rates than non-pigmented white rice seeds. This result suggests that anthocyanin, a flavonoid known to protect plants from UV irradiation, could help preserve seed viability on future space missions.
Plants are key components for systems being designed to produce nutrients and recycle carbon for future sustained space habitation, but space has been shown to reduce seed viability. Tanpopo-3, part of a series of investigations from JAXA (Japan Aerospace Exploration Agency), examined the role of anthocyanins in maintaining seed viability. Results of this and previous experiments suggest that solar light in space is more detrimental to seeds than radiation.
Preflight image of the Tanpopo panel used to expose seeds and other samples to space. Tanpopo-3 team Low-cost, autonomous technology validated for space research
Researchers verified a pair of devices for conducting experiments in space that have multi-step reactions and require automatic mixing of solutions. This type of low-cost, autonomous technology expands the possibilities for space-based research, including work by commercial entities.
Ice Cubes #6- Kirara, an investigation from ESA (European Space Agency) developed by the Japan Manned Space Systems Corporation, used a temperature-controlled incubator to crystallize proteins in microgravity. The Kirara facility also enables production of polymers, including cellulose, which have different uses than protein crystals. This experiment synthesized and decomposed cellulose.
The Kirara incubator used for experiments in microgravity. United Arab Emirates/Sultan Alneyadi Insights from observations of an X-ray binary star
Researchers used Neutron star Interior Composition Explorer (NICER) to observe the timing of 15 X-ray bursts from 4U 1820–30, an ultracompact X-ray binary (UCXB) star. An X-ray binary is a neutron star orbiting a companion from which it takes matter. If confirmed with future observations, this result makes 4U 1820–30 the fastest-spinning neutron star known in an X-ray binary system and provides insights into the physics of neutron stars.
NICER makes high-precision measurements of neutron stars (the ultra-dense matter created when massive stars explode as supernovas) and other phenomena to increase our understanding of the universe. NICER has monitored 4U 1820–30 since its launch in June 2017. A short orbital period indicates a relatively small binary system, and 4U 1820–30 has the shortest known orbital period among low-mass X-ray binaries.
Animated image of a binary star system,NASA’s Goddard Space Flight Center/Chris SmithView the full article
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.