Curious discovery: a white dwarf star with rings

Citizen scientist finds ancient white dwarf star with enigmatic dust rings

ASU astronomer Adam Schneider helps research team zero in on puzzling astrophysical object

From ARIZONA STATE UNIVERSITY

A volunteer working with the NASA-led Backyard Worlds: Planet 9 project has found the oldest and coldest known white dwarf — an old Earth-sized remnant of a sun-like star that has died — ringed by dust and debris. Astronomers suspect this could be the first known white dwarf with multiple dust rings.

The star, LSPM J0207+3331 or J0207 for short, is forcing researchers to reconsider models of planetary systems and could help us learn about the distant future of our solar system.

The star, designated LSPM J0207+3331, is the oldest, coolest white dwarf known to be surrounded by a ring of dusty debris. This illustration depicts the ring with two distinct components, which scientists think best explains the system’s infrared signal, and an asteroid broken up by the white dwarf’s gravity.
CREDIT NASA Goddard Space Flight Center/Scott Wiessinger

Adam Schneider, a research scientist at Arizona State University’s School of Earth and Space Exploration, was part of the team that unwrapped the discovery data to draw a picture of the white dwarf’s surprising details.

Backyard Worlds: Planet 9 is a project led by Marc Kuchner, an astrophysicist at NASA’s Goddard Space Flight Center. Launched two years ago, it enlists volunteers to sort through infrared data for new discoveries using an online interface and search engine.

“This object was found by Melina Thévenot of Germany using the Backyard Worlds project,” he said. “She originally thought it might be a cold brown dwarf, something the project is very interested in and has had a lot of success finding.”

Brown dwarfs are low-temperature objects too big to be planets yet too small to be stars. They shine dimly at far infrared wavelengths and because of their low luminosity, all those known lie relatively close to the sun.

“When Melina investigated further, she found that although the object had significant infrared brightness; it was not a nearby brown dwarf,” Schneider said. Instead it had to be something brighter and farther away, and the best candidate was a stellar evolution remnant: a white dwarf star.

“The team looked at it together, and we determined it was likely a white dwarf with infrared excess,” said Schneider.

Old star, warm rings

The excess was believed to be radiating from a warm, dusty circumstellar disk. Such disks are thought to result from the continual breakup of small rocky planetesimals orbiting the white dwarf. Yet with an age of roughly 3 billion years, J0207 is colder and nearly three times older than any other white dwarf known to harbor such a disk.

“However, we were brown dwarf experts and not white dwarf experts, so we needed to ‘phone- a-friend’ and contacted white dwarf expert John Debes for help interpreting what Melina had found,” said Schneider.

Debes is an astronomer at the Space Telescope Science Institute in Baltimore.

“This white dwarf is so old that whatever process is feeding material into its rings must operate on billion-year timescales,” Debes said. “Most of the models scientists have created to explain rings around white dwarfs only work well up to around 100 million years, so this star is really challenging our assumptions of how planetary systems evolve.”

Adding to the puzzle, the J0207 disk may be composed of more than one distinct ring-like component, an arrangement never before seen in circumstellar material surrounding a white dwarf.

To study the rings and their structure, Debes and Kuchner contacted collaborator Adam Burgasser at the University of California, San Diego to obtain follow-up observations with the Keck II telescope at the W. M. Keck Observatory in Hawaii.

The Keck observations helped confirm J0207’s record-setting properties. Now scientists are left to puzzle how it fits into their models.

Debes compared the population of asteroid belt analogs in white dwarf systems to the grains of sand in an hourglass. Initially, there’s a steady stream of material. The planets fling asteroids inward towards the white dwarf to be torn apart, maintaining a dusty disk. But over time, the asteroid belts become depleted, just like grains of sand in the hourglass. Eventually, all the material in the disk falls down onto the surface of the white dwarf, so older white dwarfs like J0207 should be less likely to have disks or rings.

Follow-up with future missions like NASA’s James Webb Space Telescope may help astronomers tease apart the ring’s constituent parts.

Backyard Worlds: Planet 9 bigger and better

The publication of the paper in Astrophysical Journal Letters describing the white dwarf star and rings coincides with a major upgrade of the original Backyard Worlds: Planet 9 project.

The database that volunteers search comes from NASA’s WISE satellite telescope. WISE, which stands for Wide-field Infrared Survey Explorer, was launched in late 2009 and has mapped the entire sky numerous times over the past 10 years. WISE detects infrared light, the kind of light emitted by objects at room temperature, like planets, brown dwarfs — and dusty rings around white dwarfs.

“We built Backyard Worlds: Planet 9 mostly to search for brown dwarfs and new planets in the solar system,” Kuchner said. “But working with citizen scientists always leads to surprises. They are voracious — the project just celebrated its second birthday, and they’ve already discovered more than 1,000 likely brown dwarfs. Now that we’ve rebooted the website with double the amount of WISE data, we’re looking forward to even more exciting discoveries.”

For ASU’s Schneider, the more the better.

“My job is to weed through the candidates found by the citizens, prioritize them for follow-up, and help organize the observations. It’s like a front-row seat for discoveries,” he said.

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41 thoughts on “Curious discovery: a white dwarf star with rings

  1. The star, LSPM J0207+3331 or J0207 for short, is forcing researchers to reconsider models of planetary systems and could help us learn about the distant future of our solar system.
    There goes the consensus 😊

    • ‘could help us learn about the distant future of our solar system’ is an attempt to create relevance.

      • How do you “learn” about possible future events?

        It was the word “learn” that jumped out at me when I read the article.

  2. Brown dwarfs are low-temperature objects too big to be planets yet too small to be stars. They shine dimly at far infrared wavelengths and because of their low luminosity, all those known lie relatively close to the sun.

    Am I the only one that has difficulty with this wording?

      • maybe I’m reading it totally wrong but do we have white and brown dwarf stars in our solar system close to the Sun?

        after writing that I understand they mean close to our solar system maybe within a hundred light years.

        • By close to the Sun, they mean other star systems outside our solar system. For example, the Sirius star system has a young, hot white dwarf, which orbits Sirius every fifty years. By young, they mean on the order of 120 million years old. It’s also one of the more massive white dwarfs known at about one solar mass. The Sirius star system is about 2.6 parsecs away (8.6 light-years). Sirius is the brightest star in the night sky.

          Brown dwarfs are failed stars. They are hard to detect because they are so dim. That’s why the known ones are relatively close to our solar system/Sun.

          Jim

          • and differentiating the little brown ones as “failed” may invite critism as well. It seems to imply that “success” is a status similar to Sirius.

  3. ” There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.” Mark Twain

    White dwarfs are tiny. It’s not like you can look through a telescope and actually see their rings. There’s a lot of data processing involved and that does give rise to a rather large possibility of error. link

    • Yes, much like alarmists think that all they do to track climate change is to take the temperature with thermometers all over the world for centuries, then average them and get a “we’re gonna die” number.

      Serious amount of speculation invovled in astronomy, which leads to the inevitable “forcing researchers to reconsider models” bit.

      In this case, maybe both the models and the math are wrong.

    • Yes, I am amazed that they can resolve ‘dust.’ The ‘dust’ could be boulders.

      Our knowledge of Saturn’s rings was limited until we got a satellite up there to take pictures.

  4. The system does not fit the models, and the models must be correct, just in need of tweaking. Why does that sound so familiar?

  5. Nashville weather report- rain for days. The area is bracing for potential localized flooding. Hard rain limiting visibility on most of the drive in. Weather, it’s what’s for breakfast.

    Rain or shine we have the great pleasure of beating back the watermelon nightmare every day. Also enjoy the continuing education you get here.

  6. Transport Canada Protective Direction 39 – Tank Car Phase Out

    Transport Canada Protective Direction 39 – Tank Car Phase Out
    “Transport Canada Protective Direction No. 39

    Please be advised, the Minister of Transport issued Protective Direction No.39, on September 19, 2018. This Protective Direction further accelerates the phase-out of tank cars as follows:

    Unjacketed CPC 1232 tank cars removed from crude oil service by November 1, 2018
    DOT 111 and unjacketed CPC 1232 tank cars removed from condensate and pentane service by January 1, 2019”

    Found this on the CSXT website while doing some business this morning. Maybe an effective idea and maybe not. My thought was stop pipelines and stop rail transport of oil and you stop the oil. Kind of like an Anaconda. Further on it references the “elimination of tank cars”

    • Wups! Note the “unjacketed” word, used twice.

      This isn’t eliminating oil tank cars – it is eliminating single walled tank cars. Same thing as the removal of single hulled ocean oil tankers (which was mandated for 2015).

      • Also of note, is that it specifies “removed from crude oil service”. They can still be used for other materials.

        But, yes. For crude oil you have to use double walled now. And that has already largely become the case anyway. Im pretty sure i read about them useing double walled cars for crude oild over a decade ago. Not sure when they were introduced.

        ~¿~

  7. READERS ==> FAKE PHOTO ALERT

    What appear as a magnificently detailed photograph of the star with rings is an illustration by an artists –as the artist, guided by astronomers, imagines that it might look like.

    These types of images are very common, especially from NASA. They should be clearly marked in ALL CAPS as an “artists rendition — not a photograph”

    • Thanks, k. I was suspicious when it was in color. Few astronomical photographs are in color.

      I guess there is no fun in faking B&W photos.

      • Few astronomical photographs are in color.

        Especially when your talking about infrared spectromitry.

        ^¿^

    • >>
      They should be clearly marked in ALL CAPS as an “artists rendition — not a photograph”
      <<

      I agree, but these “artists renditions” are usually obvious–in the original report.

      Jim

      • Jim ==> Or they should be obvious in the original report. This should be
        obvious to anyone who knows the tiniest but about astronomy.

        Unfortunately, the general public that reads these little science-scat reports DON’T KNOW anything about almost anything, so they see “picture” of the star with rings — and since it is connected to an article that says scientists found this star, they are most likely to assume it is a photo taken through a telescope.

        I had a teacher show a NASA image of the Milky Way — a spiral galaxy with an arrow pointing to a spot near the edge saying “You are here.” She cheerfully explained that this was a photograph of the Milky Way and that “NASA said so!” No concept of how impossible it would be to send a spacecraft out far enough to look back and take a photo of the Milky Way galaxy, how long it would take to get there, and how long it would take the image to travel back to Earth.

        As for this specific image — it is just a wild guess drawn my a clever artist.

        • >>
          She cheerfully explained that this was a photograph of the Milky Way and that “NASA said so!”
          <<

          They will have to update those old “photos” of the Milky Way. There’s evidence of a bar-shaped structure near the center of our galaxy. That would make the Milky Way a barred spiral galaxy.

          Jim

  8. “But working with citizen scientists always leads to surprises. They are voracious — the project just celebrated its second birthday, and they’ve already discovered more than 1,000 likely brown dwarfs.”

    I like this idea of citizen involvment in the science discovery process. It’s beneficial to science and must be very exciting for all the young people involved.

    There are numerous opportunities available today for the average citizen to get involved in science, and they can do so with just about any science subject they are interested in. Astronomy magazine has had a few articles about such efforts and where to go to be a part of it.

  9. ‘forcing researchers to reconsider models of planetary systems’

    So their models have been falsified.

    Oh, well. You can trust their pending new and improved models.

  10. There is so much positive in this article. The involvement of amateur astronomers. The APPRECIATION and ENCOURAGEMENT of amateur astronomer participation and what they discover. Seeking out others with different fields of expertise, i.e. sharing the discovery to get a better understanding. A true scientific perspective that posits theories, but when a new discovery disproves it, they don’t falsify data, they move forward to develop new theories and models that incorporate new knowledge.

    And maybe, just maybe, they can move forward on construction of a forge for the construction of Mjölnir.

  11. There is so much positive in this article. The involvement of amateur astronomers. The APPRECIATION and ENCOURAGEMENT of amateur astronomer participation and what they discover. Seeking out others with different fields of expertise, i.e. sharing the discovery to get a better understanding. A true scientific perspective that posits theories, but when a new discovery disproves it, they don’t falsify data, they move forward to develop new theories and models that incorporate new knowledge.

    And maybe, just maybe, they can move forward on a forge for the construction of Mjölnir.

    • Yes, its amazing that a true science that is based in observation (vs. models and theory) not only “allows” amateurs, but relies on them a great deal.

      Contrast to, say, “climate science” when “amateurs” such as Anthony and Steve McIntyre are either ignored, marginalized or outrightly smeared for their input.

      BTW, I unfortunately no longer have my “star diary” where I “discovered” Saturn with my crappy telescope back in the 70s…but I still have the scope!

    • I don’t agree, Mark Lee. The fake picture and description of ‘dusty’ mark the article as fluff from the git go.

      The involvements may be beneficial, but the article is junk. Is that Schneider’s fault, or the writer’s fault? Don’t know; don’t care.

      • It’s just possible that there’s a bit of sarcasm here. After all, a forge for the construction of Mjölnir? (Thor’s Hammer)

  12. Perhaps this white dwarf, after billions of years, just recently moved into an area containing the matter that makes up the rings. So, the age problem may not be a problem? Old star, New rings.

    • There are supposedly lots of wandering planets in the galaxy that have been ejected from their home systems, and one of them could have wandered too close to the white dwarf.

      Our Solar System supposedly had a wanderer from outside the solar system pass by just recently.

    • “Where do I sign up?”

      There have been several articles in Astronomy magazine in the last few months describing this volunteer effort and where you can sign up. The variety of science subjects included is large. It’s not just limited to astronomy.

      Unfortunately, I have been passing my copies of Astronomy magazine to a 9-year-old after I read them, so I don’t have the issues with the address available to me.

  13. “… forcing researchers to reconsider models of planetary systems.”

    Wait, what?! They said the planetary systems science was “settled”.

    • How can there be working models when it turns out nearly every astronomical object has defied expectation as more info collected, and is unique in some way? Just look at our solar system:

      Mercury – Was expected to be tidally locked to sun: 1 day per year. Found to have 3 days per 2 years instead. Orbit should have been most circular of the planets, according to expectations, but is most eccentric instead. (If Pluto isn’t a planet.)

      Venus – Has the circular orbit Mercury should have had, but rotates very slowly “backwards”. Because Earth has so much water, and Venus is totally cloud covered, it was assumed those clouds were water. They are sulfuric acid instead. Venus’ atmosphere is unexpectedly dense – 92 times denser than Earth’s.

      Earth – Unique for its water, life, plate tectonics, density, thin atmosphere, and a strangely large and distant moon.

      Mars – Its 2 moons appear to be captured asteroids, but have orbits that are at odds with expectations. Captured asteroids orbiting outer planets are common, but all have eccentric orbits at a relatively large distance from their primary. Phobos and Deimos are unusually close, relatively closer than any other moons in the solar system.

      Asteroid belt – situated at distance from the sun where a planet “should” be, going by the ratios of the spacing of all other planets’ orbits.

      Jupiter – Orbit “should” have gradually moved closer to the sun, clearing out or swallowing inner planets. That is, according to models.

      Saturn – Rings are not unusual for gas giants, but Saturn’s are exceptionally large and dense. They are not expected to last long. That we humans get to see them is considered a fluke of timing.

      Uranus – Axis of rotation is only 7 degrees different from the plane of its orbit. The poles alternately point nearly directly toward the sun. It fits the description of “laying on its side”. Very strangely, orbital planes of its moons align with axial tilt of Uranus, yet are highly regular, having little eccentricity. This goes against all expectations.

      Neptune – Its moon Titan is very much larger than its other moons (larger than Pluto) and has a retrograde orbit, making it likely that it was captured by Neptune.

      Both Uranus and Neptune are unexpectedly large. “The formation of the ice giants, Neptune and Uranus, has proven difficult to model precisely. Current models suggest that the matter density in the outer regions of the Solar System was too low to account for the formation of such large bodies from the traditionally accepted method of core accretion” From Wikipedia.

      Uranus and Neptune both have magnetic fields that do not fit the “dynamo” model. Both planet’s magnetic fields are much stronger than expected, and are tilted 59 and 47 degrees from their rotational axes, much more than expected.

      Every planet in our solar system has at least one characteristic that is so far from fitting the modeled norm, that it is hard to say there is a norm.

      SR

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