Members Can Post Anonymously On This Site
-
Similar Topics
-
By NASA
NASA/JPL-Caltech This Oct. 4, 2017, illustration shows a hypothetical uneven ring of dust orbiting KIC 8462852, also known as Boyajian’s Star or Tabby’s Star. The star has experienced unusual dips in brightness over a matter of days, as well as much subtler but longer-term dimming trends. Scientists proposed several explanations for this unexpected behavior, ranging from Tabby’s Star swallowing a planet to alien “megastructures” harvesting the star’s energy. However, a study using NASA’s Spitzer and Swift missions as well as the Belgian AstroLAB IRIS observatory suggests that the cause of the dimming over long periods is likely an uneven dust cloud moving around the star.
Learn more about this enigmatic star, named after Tabetha Boyajian, the Yale University postdoc who discovered it with the help of citizen scientists.
Image credit: NASA/JPL-Caltech
View the full article
-
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
2 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
The thermal protection system on the outside of the space shuttle included hundreds of ceramic tiles custom made for the orbiter. These reflected heat off the shuttle’s outside surface during atmospheric re-entry and were an inspiration for the ceramic ingredients in Super Therm. Credit: NASA Without proper insulation, sunlight can make buildings feel like ovens. In the late 1980s, Joseph Pritchett aimed to solve this problem by developing a coating for building insulation. He knew of NASA’s experience with thermal testing, particularly with ceramics, which have several uses for the agency. Their heat-resistant properties make them excellent materials for spacecraft reentry shields, and their durability is perfect for airplane components. Pritchett thought by infusing paints with both insulating ceramic compounds and tough, resilient polymers, he could develop an insulation coating with the best features of both.
Pritchett contacted the materials lab at NASA’s Marshall Space Flight Center in Huntsville, Alabama, through the center’s Technology Transfer Office. The facility had many ways to test heat-resistant materials, and the Marshall engineers and research scientists provided Pritchett with lists of material compounds to test for his insulation coating.
Super Therm has been applied in several places, including handrails on the Hoover Dam Bypass Bridge over the Colorado River. The selection of its makeup of ceramic and polymeric materials was assisted by NASA scientists.Credit: Superior Products InternationaI II, LLC Over a period of six years, Pritchett tested every compound on the lists NASA provided, narrowing down the potential compounds until he found the ideal insulation. Pritchett founded Superior Products International II, Inc. of Shawnee, Kansas, in 1995. His product, dubbed Super Therm, is a composite of both ceramic and polymeric materials. In 2011, when tested by Oak Ridge National Laboratory in Tennessee, Pritchett’s product proved successful in saving energy when cooling homes.
The engineers at Marshall played a pivotal role in Super Therm’s development, as their knowledge was key to finding the right ceramic material. In addition to insulation for buildings, the material has been used in other industrial applications, such as keeping equipment like tanks and pumps cool on oil rigs. Pritchett’s Super Therm is yet another example of how NASA’s Technology Transfer Program within the agency’s Space Technology Mission Directorate drives innovation in commercial industry.
Read More Share
Details
Last Updated Nov 19, 2024 Related Terms
Technology Transfer & Spinoffs Spinoffs Technology Transfer Explore More
2 min read From Mars Rovers to Factory Assembly Lines
NASA-funded AI technology enabling autonomous rovers and drones now keeps an eye on conveyor belts
Article 3 weeks ago 2 min read The View from Space Keeps Getting Better
After 50 years of Landsat, discovery of new commercial and scientific uses is only accelerating
Article 1 month ago 2 min read Controlled Propulsion for Gentle Landings
A valve designed for NASA rover landings enables effective stage separations for commercial spaceflight
Article 1 month ago Keep Exploring Discover Related Topics
Technology Transfer & Spinoffs
Thermal Protection Materials Branch
Marshall Space Flight Center
Technology
View the full article
-
By NASA
Hubble Space Telescope Home Hubble Takes a Look at Tangled… 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 2 min read
Hubble Takes a Look at Tangled Galaxies
This Hubble image features a pair of interacting spiral galaxies called MCG+05-31-045. ESA/Hubble & NASA, R. J. Foley (UC Santa Cruz)
Download this image
This NASA/ESA Hubble Space Telescope image depicts the cosmic tangle that is MCG+05-31-045, a pair of interacting galaxies located 390 million light-years away and a part of the Coma galaxy cluster.
The Coma Cluster is a particularly rich cluster that contains over a thousand known galaxies. Amateur astronomers can easily spot several of these in a backyard telescope (See Caldwell 35). Most of them are elliptical galaxies, and that’s typical of a dense galaxy cluster like the Coma Cluster: many elliptical galaxies form through close encounters between galaxies that stir them up, or even collisions that rip them apart. While the stars in interacting galaxies can stay together, their gas is twisted and compressed by gravitational forces and rapidly used up to form new stars. When the hot, massive, blue stars die, there is little gas left to form new generations of young stars to replace them. As spiral galaxies interact, gravity disrupts the regular orbits that produce their striking spiral arms. Whether through mergers or simple near misses, the result is a galaxy almost devoid of gas, with aging stars orbiting in uncoordinated circles: an elliptical galaxy.
It’s very likely that a similar fate will befall MCG+05-31-045. As the smaller spiral galaxy is torn up and integrated into the larger galaxy, many new stars will form, and the hot, blue ones will quickly burn out, leaving cooler, redder stars behind in an elliptical galaxy, much like others in the Coma Cluster. But this process won’t be complete for many millions of years.
Explore more Coma Cluster images from Hubble.
Hubble Uncovers Thousands of Globular Star Clusters Scattered Among Galaxies Hubble’s Galaxies With Knots, Bursts Hubble Sees Near and Far Hubble Sees Plunging Galaxy Losing Its Gas Hubble Catches Galaxies Swarmed by Star Clusters Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubble Media Contact:
Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov
Share
Details
Last Updated Nov 14, 2024 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
Astrophysics Astrophysics Division Hubble Space Telescope Spiral Galaxies 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.
Galaxy Details and Mergers
Hubble’s Galaxies
Explore the Night Sky
View 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.