Jump to content

Recommended Posts

  • Publishers
Posted
4 Min Read

NASA’s Hubble Tracks Down a ‘Blue Lurker’ Among Stars

Illustration titled “Evolution of 'Blue Lurker' Star System.” It features six boxes, in two rows of three. The top left shows a large circular path of a star surrounding a small circular path of two rotating stars. The top middle box shows two stars rotating around each other, shown with blue streaks, and a third star is in the distance. The top right box shows a large fiery orange star with a feeding line to another distant star. The bottom left box shows a small yellow star on a black background surrounded by a faint red ring of gas. The bottom middle box shows the yellow star with a white box around it. Lines lead from this small box to the bottom right panel, showing a large fiery yellow star. The words “Artist's Concept” is at the bottom right.
Evolution of a “Blue Lurker” Star in a Triple System
Credits:
NASA, ESA, Leah Hustak (STScI)

The name “blue lurker” might sound like a villainous character from a superhero movie. But it is a rare class of star that NASA’s Hubble Space Telescope explored by looking deeply into the open star cluster M67, roughly 2,800 light-years away.

Forensics with Hubble data show that the star has had a tumultuous life, mixing with two other stars gravitationally bound together in a remarkable triple-star system. The star has a kinship to so-called “blue stragglers,” which are hotter, brighter, and bluer than expected because they are likely the result of mergers between stars.

Illustration titled “Evolution of 'Blue Lurker' Star System.” It features six boxes, in two rows of three. The top left shows a large circular path of a star surrounding a small circular path of two rotating stars. The top middle box shows two stars rotating around each other, shown with blue streaks, and a third star is in the distance. The top right box shows a large fiery orange star with a feeding line to another distant star. The bottom left box shows a small yellow star on a black background surrounded by a faint red ring of gas. The bottom middle box shows the yellow star with a white box around it. Lines lead from this small box to the bottom right panel, showing a large fiery yellow star. The words “Artist's Concept” is at the bottom right.
Evolution of a “Blue Lurker” Star in a Triple System Panel 1: A triple star system containing three Sun-like stars. Two are very tightly orbiting. The third star has a much wider orbit. Panel 2: The close stellar pair spiral together and merge to form one more massive star. Panel 3: The merged star evolves into a giant star. As the huge photosphere expands, some of the material falls onto the outer companion, causing the companion to grow larger and its rotation rate to increase. Panels 4-5: The central merged star eventually burns out and forms a massive white dwarf, and the outer companion spirals in towards the white dwarf, leaving a binary star system with a tighter orbit. Panel 6: The surviving outer companion is much like our Sun but nicknamed a “blue lurker.” Although it is slightly brighter bluer than expected because of the earlier mass-transfer from the central star and is now rotating very rapidly, these features are subtle. The star could easily be mistaken for a normal Sun-like star despite its exotic evolutionary history.
NASA, ESA, Leah Hustak (STScI)

The blue lurker is spinning much faster than expected, an unusual behavior that led to its identification. Otherwise it looks like a normal Sun-like star. The term “blue” is a bit of a misnomer because the star’s color blends in with all the other solar-mass stars in the cluster. Hence it is sort of “lurking” among the common stellar population.

The spin rate is evidence that the lurker must have siphoned in material from a companion star, causing its rotation to speed up. The star’s high spin rate was discovered with NASA’s retired Kepler space telescope. While normal Sun-like stars typically take about 30 days to complete one rotation, the lurker takes only four days.

How the blue lurker got that way is a “super complicated evolutionary story,” said Emily Leiner of Illinois Institute of Technology in Chicago. “This star is really exciting because it’s an example of a star that has interacted in a triple-star system.” The blue lurker originally rotated more slowly and orbited a binary system consisting of two Sun-like stars.

Around 500 million years ago, the two stars in that binary merged, creating a single, much more massive star. This behemoth soon swelled into a giant star, dumping some of its own material onto the blue lurker and spinning it up in the process. Today, we observe that the blue lurker is orbiting a white dwarf star — the burned out remains of the massive merger.

“We know these multiple star systems are fairly common and are going to lead to really interesting outcomes,” Leiner explained. “We just don’t yet have a model that can reliably connect through all of those stages of evolution. Triple-star systems are about 10 percent of the Sun-like star population. But being able to put together this evolutionary history is challenging.”

Hubble observed the white dwarf companion star that the lurker orbits. Using ultraviolet spectroscopy, Hubble found the white dwarf is very hot (as high as 23,000 degrees Fahrenheit, or roughly three times the Sun’s surface temperature) and a heavyweight at 0.72 solar masses. According to theory, hot white dwarfs in M67 should be only about 0.5 solar masses. This is evidence that the white dwarf is the byproduct of the merger of two stars that once were part of a triple-star system.

“This is one of the only triple systems where we can tell a story this detailed about how it evolved,” said Leiner. “Triples are emerging as potentially very important to creating interesting, explosive end products. It’s really unusual to be able to put constraints on such a system as we are exploring.”

Leiner’s results are being presented at the 245th meeting of the American Astronomical Society in Washington, D.C.

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.

Media Contact:

Claire Andreoli (claire.andreoli@nasa.gov)
NASA’s Goddard Space Flight CenterGreenbelt, MD

Ray Villard
Space Telescope Science Institute, Baltimore, MD

Science Contact:

Emily Leiner
Illinois Institute of Technology, Chicago, IL

Share

Details

Last Updated
Jan 13, 2025
Editor
Andrea Gianopoulos

View the full article

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.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Topics

    • By NASA
      Explore Hubble 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 Online Activities Lithographs Fact Sheets Posters Hubble on the NASA App Glossary More 35th Anniversary Online Activities 5 Min Read 20-Year Hubble Study of Uranus Yields New Atmospheric Insights
      The image columns show the change of Uranus for the four years that STIS observed Uranus across a 20-year period. Over that span of time, the researchers watched the seasons of Uranus as the south polar region darkened going into winter shadow while the north polar region brightened as northern summer approaches. Credits:
      NASA, ESA, Erich Karkoschka (LPL) The ice-giant planet Uranus, which travels around the Sun tipped on its side, is a weird and mysterious world. Now, in an unprecedented study spanning two decades, researchers using NASA’s Hubble Space Telescope have uncovered new insights into the planet’s atmospheric composition and dynamics. This was possible only because of Hubble’s sharp resolution, spectral capabilities, and longevity. 
      The team’s results will help astronomers to better understand how the atmosphere of Uranus works and responds to changing sunlight. These long-term observations provide valuable data for understanding the atmospheric dynamics of this distant ice giant, which can serve as a proxy for studying exoplanets of similar size and composition.
      When Voyager 2 flew past Uranus in 1986, it provided a close-up snapshot of the sideways planet. What it saw resembled a bland, blue-green billiard ball. By comparison, Hubble chronicled a 20-year story of seasonal changes from 2002 to 2022. Over that period, a team led by Erich Karkoschka of the University of Arizona, and Larry Sromovsky and Pat Fry from the University of Wisconsin used the same Hubble instrument, STIS (the Space Telescope Imaging Spectrograph), to paint an accurate picture of the atmospheric structure of Uranus. 
      Uranus’ atmosphere is mostly hydrogen and helium, with a small amount of methane and traces of water and ammonia. The methane gives Uranus its cyan color by absorbing the red wavelengths of sunlight.
      The Hubble team observed Uranus four times in the 20-year period: in 2002, 2012, 2015, and 2022. They found that, unlike conditions on the gas giants Saturn and Jupiter, methane is not uniformly distributed across Uranus. Instead, it is strongly depleted near the poles. This depletion remained relatively constant over the two decades. However, the aerosol and haze structure changed dramatically, brightening significantly in the northern polar region as the planet approaches its northern summer solstice in 2030.
      The image columns show the change of Uranus for the four years that STIS observed Uranus across a 20-year period. Over that span of time, the researchers watched the seasons of Uranus as the south polar region darkened going into winter shadow while the north polar region brightened as northern summer approaches. NASA, ESA, Erich Karkoschka (LPL) Uranus takes a little over 84 Earth years to complete a single orbit of the Sun. So, over two decades, the Hubble team has only seen mostly northern spring as the Sun moves from shining directly over Uranus’ equator toward shining almost directly over its north pole in 2030. Hubble observations suggest complex atmospheric circulation patterns on Uranus during this period. The data that are most sensitive to the methane distribution indicate a downwelling in the polar regions and upwelling in other regions. 
      The team analyzed their results in several ways. The image columns show the change of Uranus for the four years that STIS observed Uranus across a 20-year period. Over that span of time, the researchers watched the seasons of Uranus as the south polar region (left) darkened going into winter shadow while the north polar region (right) brightened as it began to come into a more direct view as northern summer approaches.
      The top row, in visible light, shows how the color of Uranus appears to the human eye as seen through even an amateur telescope. 
      In the second row, the false-color image of the planet is assembled from visible and near-infrared light observations. The color and brightness correspond to the amounts of methane and aerosols. Both of these quantities could not be distinguished before Hubble’s STIS was first aimed at Uranus in 2002. Generally, green areas indicate less methane than blue areas, and red areas show no methane. The red areas are at the limb, where the stratosphere of Uranus is almost completely devoid of methane. 
      The two bottom rows show the latitude structure of aerosols and methane inferred from 1,000 different wavelengths (colors) from visible to near infrared. In the third row, bright areas indicate cloudier conditions, while the dark areas represent clearer conditions. In the fourth row, bright areas indicate depleted methane, while dark areas show the full amount of methane. 
      At middle and low latitudes, aerosols and methane depletion have their own latitudinal structure that mostly did not change much over the two decades of observation.  However, in the polar regions, aerosols and methane depletion behave very differently. 
      In the third row, the aerosols near the north pole display a dramatic increase, showing up as very dark during early northern spring, turning very bright in recent years. Aerosols also seem to disappear at the left limb as the solar radiation disappeared. This is evidence that solar radiation changes the aerosol haze in the atmosphere of Uranus. On the other hand, methane depletion seems to stay quite high in both polar regions throughout the observing period. 
      Astronomers will continue to observe Uranus as the planet approaches northern summer.
      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 Related Images & Videos
      20 Years of Uranus Observations





      Share








      Details
      Last Updated Mar 31, 2025 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center
      Contact Media Claire Andreoli
      NASA’s Goddard Space Flight Center
      Greenbelt, Maryland
      claire.andreoli@nasa.gov
      Ann Jenkins
      Space Telescope Science Institute, Baltimore, Maryland
      Ray Villard
      Space Telescope Science Institute, Baltimore, Maryland

      Related Terms
      Hubble Space Telescope Astrophysics Division Goddard Space Flight Center Planetary Environments & Atmospheres Planetary Science Planets The Solar System Uranus
      View the full article
    • By NASA
      Explore Hubble 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 Online Activities Lithographs Fact Sheets Posters Hubble on the NASA App Glossary More 35th Anniversary Online Activities 2 min read
      Hubble Spots a Chance Alignment
      This NASA/ESA Hubble image features the spiral galaxy NGC 5530. ESA/Hubble & NASA, D. Thilker The subject of today’s NASA/ESA Hubble Space Telescope image is the stunning spiral galaxy NGC 5530. This galaxy is situated 40 million light-years away in the constellation Lupus, the Wolf, and classified as a ‘flocculent’ spiral, meaning its spiral arms are patchy and indistinct.
      While some galaxies have extraordinarily bright centers that host a feasting supermassive black hole, the bright source near the center of NGC 5530 is not an active black hole but a star within our own galaxy, only 10,000 light-years from Earth. This chance alignment gives the appearance that the star is at the dense heart of NGC 5530.
      If you pointed a backyard telescope at NGC 5530 on the evening of September 13, 2007, you would have seen another bright point of light adorning the galaxy. That night, Australian amateur astronomer Robert Evans discovered a supernova, named SN 2007IT, by comparing NGC 5530’s appearance through the telescope to a reference photo of the galaxy. While it’s remarkable to discover even one supernova using this painstaking method, Evans has in fact discovered more than 40 supernovae this way! This particular discovery was truly serendipitous: it’s likely that the light from the supernova completed its 40-million-year journey to Earth just days before Evans spotted the explosion.
      Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubble Share








      Details
      Last Updated Mar 28, 2025 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
      Hubble Space Telescope Astrophysics Astrophysics Division Galaxies Goddard Space Flight Center Spiral Galaxies The Universe 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.


      Hubble’s Galaxies



      Hubble’s 35th Anniversary



      Hubble’s Night Sky Challenge


      View the full article
    • By NASA
      1 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      NASA’s LRO (Lunar Reconnaissance Orbiter) imaged Firefly Aerospace’s Blue Ghost Mission 1 lunar lander on the Moon’s surface the afternoon of March 2, not quite 10 hours after the spacecraft landed.
      Firefly Aerospace’s Blue Ghost Mission 1 lunar lander, which appears in this image from NASA’s Lunar Reconnaissance Orbiter as a bright pixel casting a shadow in the middle of the white box, reached the surface of the Moon on March 2 at 3:34 a.m. EST.NASA/Goddard/Arizona State University The delivery is part of NASA’s CLPS (Commercial Lunar Payload Services) initiative and Artemis campaign. This is the first CLPS delivery for Firefly, and their first Moon landing.
      LRO is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland, for the Science Mission Directorate at NASA Headquarters in Washington. Launched on June 18, 2009, LRO has collected a treasure trove of data with its seven powerful instruments, making an invaluable contribution to our knowledge about the Moon. NASA is returning to the Moon with commercial and international partners to expand human presence in space and bring back new knowledge and opportunities.
      More on this story from Arizona State University’s LRO Camera website
      Media Contact:
      Nancy N. Jones
      NASA’s Goddard Space Flight Center, Greenbelt, Md.
      Share
      Details
      Last Updated Mar 25, 2025 Related Terms
      Lunar Reconnaissance Orbiter (LRO) View the full article
    • By NASA
      Explore Hubble 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 Online Activities Lithographs Fact Sheets Posters Hubble on the NASA App Glossary More 35th Anniversary Online Activities 2 min read
      Hubble Captures a Neighbor’s Colorful Clouds
      This NASA/ESA Hubble Space Telescope image features part of the Small Magellanic Cloud. ESA/Hubble & NASA, C. Murray
      Download this image

      Say hello to one of the Milky Way’s neighbors! This NASA/ESA Hubble Space Telescope image features a scene from one of the closest galaxies to the Milky Way, the Small Magellanic Cloud (SMC). The SMC is a dwarf galaxy located about 200,000 light-years away. Most of the galaxy resides in the constellation Tucana, but a small section crosses over into the neighboring constellation Hydrus.
      Thanks to its proximity, the SMC is one of only a few galaxies that are visible from Earth without the help of a telescope or binoculars. For viewers in the southern hemisphere and some latitudes in the northern hemisphere, the SMC resembles a piece of the Milky Way that has broken off, though in reality it’s much farther away than any part of our own galaxy.
      With its 2.4-meter mirror and sensitive instruments, Hubble’s view of the SMC is far more detailed and vivid than what humans can see. Researchers used Hubble’s Wide Field Camera 3 to observe this scene through four different filters. Each filter permits different wavelengths of light, creating a multicolored view of dust clouds drifting across a field of stars. Hubble’s view, however, is much more zoomed-in than our eyes, allowing it to observe very distant objects. This image captures a small region of the SMC near the center of NGC 346, a star cluster that is home to dozens of massive young stars.
      Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubble Media Contact:
      Claire Andreoli (claire.andreoli@nasa.gov)
      NASA’s Goddard Space Flight Center, Greenbelt, MD
      Share








      Details
      Last Updated Mar 21, 2025 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
      Hubble Space Telescope Astrophysics Astrophysics Division Galaxies Goddard Space Flight Center Magellanic Clouds The Universe 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.


      Hubble’s Night Sky Challenge



      Hearing Hubble



      Reshaping Our Cosmic View: Hubble Science Highlights


      View the full article
    • By NASA
      Views: Splashing Down On Earth
  • Check out these Videos

×
×
  • Create New...