A volunteer working with the NASA-led Backyard Worlds: Planet 9<\/a><\/em> project has found the oldest and coldest known white dwarf \u2014 an Earth-sized remnant of a Sun-like star that has died \u2014 ringed by dust and debris. Astronomers suspect this could be the first known white dwarf with multiple dust rings.<\/p>\n 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.<\/p>\n \u201cThis white dwarf is so old that whatever process is feeding material into its rings must operate on billion-year timescales,\u201d said John Debes, an astronomer at the Space Telescope Science Institute<\/a> in Baltimore. \u201cMost 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.\u201d<\/em><\/p>\n A paper detailing the findings, led by Debes, was published in the Feb. 19 issue of The Astrophysical Journal Letters and is now available online<\/a>.<\/p>\n J0207 is located around 145 light-years away in the constellation Capricornus<\/a>. White dwarfs slowly cool as they age, and Debes\u2019 team calculated J0207 is about 3 billion years old based on a temperature just over 10,500 degrees Fahrenheit (5,800 degrees Celsius). A strong infrared signal picked up by NASA\u2019s Wide-field Infrared Survey Explorer (WISE)<\/a> mission \u2014 which mapped the entire sky in infrared light \u2014 suggested the presence of dust, making J0207 the oldest and coldest white dwarf with dust yet known. Previously, dust disks and rings had only been observed surrounding white dwarfs about one-third J0207\u2019s age.<\/p>\n When a Sun-like star runs out of fuel, it swells into a red giant, ejects at least half of its mass, and leaves behind a very hot white dwarf<\/a>. Over the course of the star\u2019s giant phase, planets and asteroids close to the star become engulfed and incinerated. Planets and asteroids farther away survive, but move outward as their orbits expand. That\u2019s because when the star loses mass, its gravitational influence on surrounding objects is greatly reduced.<\/p>\n This scenario describes the future of our solar system. Around 5 billion years from now, Mercury, then Venus and possibly Earth will be swallowed when the Sun grows into a red giant. Over hundreds of thousands to millions of years, the inner solar system will be scrubbed clean, and the remaining planets will drift outward.<\/p>\n Yet some white dwarfs \u2014 between 1 and 4 percent \u2014 show infrared emission indicating they\u2019re surrounded by dusty disks or rings. Scientists think the dust may arise from distant asteroids and comets kicked closer to the star by gravitational interactions with displaced planets<\/a>. As these small bodies approach the white dwarf, the star\u2019s strong gravity tears them apart in a process called tidal disruption. The debris forms a ring of dust that will slowly spiral down onto the surface of the star.<\/p>\n J0207 was found through Backyard Worlds: Planet 9<\/a><\/em>, a project led by Marc Kuchner, a co-author and astrophysicist at NASA\u2019s Goddard Space Flight Center in Greenbelt, Maryland, that asks volunteers to sort through WISE data for new discoveries.<\/p>\n Melina Th\u00e9venot, a co-author and citizen scientist<\/a> in Germany working with the project, initially thought the infrared signal was bad data. She was searching through the ESA\u2019s (European Space Agency\u2019s)<\/a> Gaia<\/a> archives for brown dwarfs, objects too large to be planets and too small to be stars, when she noticed J0207. When she looked at the source in the WISE infrared data, it was too bright and too far away to be a brown dwarf. Th\u00e9venot passed her findings along to the Backyard Worlds: Planet 9 team. 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<\/a> in Hawaii.<\/p>\n \u201cThat is a really motivating aspect of the search,\u201d said Th\u00e9venot, one of more than 150,000 citizen scientists on the Backyard Worlds project. \u201cThe researchers will move their telescopes to look at worlds you have discovered. What I especially enjoy, though, is the interaction with the awesome research team. Everyone is very kind, and they are always trying to make the best out of our discoveries.\u201d<\/em><\/p>\n The Keck observations helped confirm J0207\u2019s record-setting properties. Now scientists are left to puzzle how it fits into their models.<\/p>\n Debes compared the population of asteroid belt analogs in white dwarf systems to the grains of sand in an hourglass. Initially, there\u2019s 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.<\/p>\n J0207\u2019s ring may even be multiple rings. Debes and his colleagues suggest there could be two distinct components, one thin ring just at the point where the star\u2019s tides break up the asteroids and a wider ring closer to the white dwarf. Follow-up with future missions like NASA’s James Webb Space Telescope<\/a> may help astronomers tease apart the ring\u2019s constituent parts.<\/p>\n \u201cWe built Backyard Worlds: Planet 9 mostly to search for brown dwarfs and new planets in the solar system,\u201d Kuchner said. \u201cBut working with citizen scientists always leads to surprises. They are voracious \u2014 the project just celebrated its second birthday, and they\u2019ve already discovered more than 1,000 likely brown dwarfs. Now that we\u2019ve rebooted the website with double the amount of WISE data, we\u2019re looking forward to even more exciting discoveries.\u201d\u00a0\u00a0<\/em><\/p>\n Backyard Worlds: Planet 9<\/em> is a collaboration between NASA, the American Museum of Natural History in New York, Arizona State University, National Optical Astronomy Observatory, the Space Telescope Science Institute in Baltimore, the University of California San Diego, Bucknell University, the University of Oklahoma, and Zooniverse, a collaboration of scientists, software developers and educators who collectively develop and manage citizen science projects on the internet.<\/p>\n NASA’s Jet Propulsion Laboratory in Pasadena, California, manages and operates WISE for NASA’s Science Mission Directorate. The WISE mission was selected competitively under NASA’s Explorers Program managed by the agency’s Goddard Space Flight Center. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah. The spacecraft was built by Ball Aerospace & Technologies Corp. in Boulder, Colorado. Placed in hibernation in 2011, the spacecraft was reactivated in 2013 and renamed NEOWISE. Science operations and data processing take place at the Infrared Processing and Analysis Center at Caltech, which manages JPL for NASA.<\/p>\n For more information about Backyard Worlds: Planet<\/em> 9, visit:\u00a0http:\/\/backyardworlds.org<\/a><\/p>\n For more information about NASA’s WISE mission, visit:\u00a0http:\/\/www.nasa.gov\/wise<\/a><\/p>\n By Jeanette Kazmierczak<\/a> ====<\/p>\n As often reported here, citizen scientists, especially in astronomy, continue to make significant contributions to the sciences. Here is a new article from NASA detailing one such case: Citizen Scientist Finds Ancient White Dwarf Star With Puzzling Rings A volunteer working with the NASA-led Backyard Worlds: Planet 9 project has found the oldest and coldest … Continue reading Citizen Scientist in NASA project spots ancient white dwarf star with puzzling rings<\/span> ![\"\"](\"http:\/\/hobbyspace.com\/Blog\/wp-content\/uploads\/2019\/02\/white_dwarf_disk_final1.jpg\")
<\/a>![\"\"](\"http:\/\/hobbyspace.com\/Blog\/wp-content\/uploads\/2019\/02\/White_Dwarf_Flipbook.gif\")
<\/a>
Credit: Backyard Worlds: Planet 9\/NASA\u2019s Goddard Space Flight Center<\/em><\/a><\/figcaption><\/figure>\n![\"\"](\"http:\/\/hobbyspace.com\/Blog\/wp-content\/uploads\/2019\/02\/White_Dwarf_Zoom_to_Dot1.gif\")
<\/a>
\nNASA\u2019s Goddard Space Flight Center<\/a>, Greenbelt, Md.<\/p>\n![\"\"](\"\/\/ir-na.amazon-adsystem.com\/e\/ir?t=hobbyspace&l=ur2&o=1\")