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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
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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
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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
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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.
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By NASA
Earth Observer Earth Home Earth Observer Home Editor’s Corner Feature Articles Meeting Summaries News Science in the News Calendars In Memoriam More Archives 3 min read
Summary of Aura 20th Anniversary Event
Snippets from The Earth Observer’s Editor’s Corner
The last of NASA’s three EOS Flagships – Aura – marked 20 years in orbit on July 15, 2024, with a celebration on September 18, 2024, at the Goddard Space Flight Center’s (GSFC) Recreational Center. The 120 attendees – including about 40 virtually – reminisced about Aura’s (originally named EOS-CHEM) tumultuous beginning, from the instrument and Principal Investigator (PI) selections up until the delayed launch at the Vandenberg Space Force Base (then Vandenberg Air Force Base) in California. They remembered how Bill Townsend, who was Deputy Director of GSFC at the time, and Ghassem Asrar, who was NASA’s Associate Administrator for Earth Science, spent many hours on site negotiating with the Vandenberg and Boeing launch teams in preparation for launch (after several delays and aborts). The Photo shows the Aura mission program scientist, project scientists (PS), and several instrument principal investigators (PI) shortly before launch.
Photo 1. The Aura (formerly EOS CHEM) mission program scientist, project scientists (PS), and several of instrument principal investigators (PI) at Vandenberg Space Force Base (then Air Force Base) shortly before launch on July 15, 2004. The individuals pictured [left to right] are Reinhold Beer [NASA/Jet Propulsion Laboratory (JPL)—Tropospheric Emission Spectrometer (TES) PI]; John Gille [University of Colorado, Boulder/National Center for Atmospheric Research (NCAR)—High Resolution Dynamics Limb Sounder (HIRDLS) PI]; Pieternel Levelt [Koninklijk Nederlands Meteorologisch Instituut (KNMI), Royal Netherlands Meteorological Institute—Ozone Monitoring Instrument (OMI) PI]; Ernest Hilsenrath [NASA’s Goddard Space Flight Center (GSFC)—Aura Deputy Scientist and U.S. OMI Co-PI];Anne Douglass [GSFC—Aura Deputy PS]; Mark Schoeberl [GSFC—Aura Project Scientist]; Joe Waters [NASA/JPL—Microwave Limb Sounder (MLS) PI]; P.K. Bhartia [GSFC—OMI Science Team Leader and former Aura Project Scientist]; and Phil DeCola [NASA Headquarters—Aura Program Scientist]. NOTE: Affiliations/titles listed for individuals named were those at the time of launch. Photo Credit: Ernest Hilsenrath At the anniversary event, Bryan Duncan [GSFC—Aura Project Scientist] gave formal opening remarks. Aura’s datasets have given a generation of scientists the most comprehensive global view of gases in Earth’s atmosphere to better understand the chemical and dynamic processes that shape their concentrations. Aura’s objective was to gather data to monitor Earth’s ozone layer, examine trends in global air pollutants, and measure the concentration of atmospheric constituents contributing to climate forcing. To read more about Aura’s incredible 20 years of accomplished air quality and climate science, see the anniversary article “Aura at 20 Years” in The Earth Observer.
Bill Guit [GSFC—Aqua and Aura Program Manager and former Aura Mission Operations Lead] gave brief remarks focusing on how Aura became part of the international Afternoon Constellation, or “A-Train,” of satellites, including Aqua, which launched in 2002, and joined by several other NASA and international missions. Aura and Aqua have provided data for over two decades of multidisciplinary Earth science discovery and enhancement.
Both current and former Aura instrument PIs gave brief remarks. Each discussed Aura’s scientific legacy and their instrument’s contributions. They thanked their engineering teams for the successful development and operation of their instruments, and the members of the instrument science teams for developing the algorithms, discovering new science, and demonstrating how the science will serve the public. The PIs were particularly grateful that their instruments or the variants thereof will continue to fly on current and/or future NASA science missions or on international operational satellites.
Steve Platnick
EOS Senior Project Scientist
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Last Updated Nov 14, 2024 Related Terms
Earth Science View the full article
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By NASA
1 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Shauntina Lilly, a NASA Glenn public affairs officer, speaks to students about NASA’s available internships and educational resources during the STEM Goes Red for Girls event at Great Lakes Science Center, home of the NASA Glenn Visitor Center, on Oct. 21.Credit: NASA/Debbie Welch NASA’s Glenn Research Center in Cleveland supported this year’s STEM Goes Red for Girls event at Great Lakes Science Center on Oct. 21. The program provides seventh and eighth grade students exposure to some of Greater Cleveland’s leading STEM companies. The event also featured a hands-on exhibitor fair, speed mentoring, and educational classes.
Hosted by the American Heart Association, this year’s event welcomed its largest audience to date with 352 students and educators from 32 schools within Northeast Ohio. NASA Glenn’s presence focused heavily on internships and career advice, but also highlighted the center’s work with the Space Communications and Navigation program’s Deep Space Network. Glenn’s Julie Sufka also served as a mentor, speaking to young girls about STEM opportunities in mathematics.
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1 min read NASA Glenn Chief Counsel Named to CSU Law Hall of Fame
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By Space Force
Six pioneers in American space and missile development were honored in a ceremony hosted by Space Systems Command recognizing achievements in astronautics that resonate in today’s contested space environment.
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By NASA
3 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Shauntina Lilly, a NASA Glenn public affairs officer, smiles as she speaks to students about NASA’s available internships and educational resources during the STEM Goes Red for Girls event at Great Lakes Science Center, home of the NASA Glenn Visitor Center, on October 21.Credit: NASA/Debbie Welch NASA is making event plans for the 2025 calendar year, and we want to pencil you in! We are looking for the Midwest’s biggest and best community events with the broadest audiences to share NASA’s content and raise awareness of the agency’s most exciting aeronautics and space missions. NASA’s Glenn Research Center in Cleveland is leading the agency’s efforts to inspire the Midwest through engagement.
Learn How to Submit a Proposal
Interested organizations can submit an event proposal to Glenn now through Nov. 18, 2024. Those selected will receive notification via email by Dec. 31, 2024. Through this collaboration, selected organizations will gain access to NASA exhibits and artifacts, hands-on demonstrations, STEM and internship opportunities for students and educators, NASA’s innovative technology, and experts that align to the topics and themes of their events.
Eligibility Requirements
NASA is seeking:
Organizations with direct community connections and an established event that reaches diverse audiences. Events scheduled to occur between Jan. 1, 2025, and Dec. 31, 2025. Events that are mutually beneficial – where a NASA presence will enhance the event experience and raise awareness of NASA’s contributions to the advancement of aeronautics and space exploration. Selected organizations must agree to the following:
Attend virtual planning meetings through an online business communication platform. Work with NASA Glenn’s Office of Communications when coordinating marketing, media communications, and logistics as described in the event proposal. Adhere to NASA Media Usage Guidelines for NASA media and logos. Provide final attendance data within two weeks of the conclusion of the event including the following: Number of attendees Estimated percentage of attendees from underrepresented audiences Submitting a Proposal
All proposals are to be submitted through the online proposal form. Proposals must be submitted by 11:59 p.m. Eastern on Nov. 18, 2024. Only proposals submitted online will be accepted.
Proposal Review Process
Proposals will be evaluated and scored, and selections will be made using the following criteria:
Estimated audience size. Percentage of audience from underserved and/or underrepresented communities as defined below. For purposes of this solicitation, underserved and/or underrepresented communities include Black, Latino, and Indigenous and Native American persons, Asian Americans and Pacific Islanders and other persons of color; members of religious minorities; lesbian, gay, bisexual, transgender, and queer (LGBTQ+) persons; persons with disabilities; persons who live in rural areas; and persons otherwise adversely affected by persistent poverty or inequality. (Source: NASA’s Mission Equity). Alignment of the program’s goals and objectives to those of this opportunity. Plans to maximize audience participation through marketing and media communications. Evidence of historical attendance at this or similar events hosted by the proposing organization. Proposing organizations will be notified of their selection status by Dec. 31, 2024.
Point of Contact
If you have questions about this opportunity or the online proposal form, contact NASA Glenn’s Office of Communications: GRC-Public-Engagement@mail.nasa.gov.
Timeline
Solicitation posted: Oct. 23, 2024
Proposal form URL: https://osirris.grc.nasa.gov/request/request.cfm
Proposal submission deadline: Nov. 18, 2024
Notification of event selection: Dec. 13, 2024
Background
NASA’s Glenn Research Center designs, develops, and tests innovative technology to revolutionize air travel, advance space exploration, and improve life on Earth. As one of 10 NASA centers, and the only one in the Midwest, Glenn is a vital contributor to the region’s economy and culture. Many NASA missions have Glenn contributions, and every U.S. aircraft has NASA Glenn technology on board, making flight cleaner, safer, and quieter.
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