Using the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers have imaged the debris disk of nearby star HD 53143 at millimeter wavelengths for the first time, and it appears that nothing as they expected. Based on early coronagraphic data, scientists expected ALMA to confirm that the debris disk was a face-on ring strewn with dust particles. Instead, the observations took a surprising turn, revealing the most complicated and eccentric debris disk yet observed. The observations were presented today at a press conference at the 240th meeting of the American Astronomical Society (AAS) in Pasadena, California, and will be published in a forthcoming issue of The Astrophysical Journal Letters (ApJL).
HD 53143 — a roughly billion-year-old Sun-like star 59.8 light-years from Earth in the constellation Carina — was first observed with the coronagraphic Advanced Camera for Surveys on the Hubble Space Telescope (HST) in 2006. surrounded by a debris disk — a belt of comets orbiting a star that continually collide and grind into smaller dust and debris — what scientists previously thought was a face-on ring resembling the debris disk around our sun, better known like the Kuiper Belt.
The new observations were made from HD 53143 using the highly sensitive Band 6 receivers at ALMA, an observatory partnered by the US National Science Foundation’s National Radio Astronomy Observatory (NRAO), and revealed that the debris disk from the U.S. galaxy in fact very eccentric. In annular debris disks, the star is usually in or near the center of the disk. But in elliptically shaped eccentric disks, the star is in one focus of the ellipse, far away from the center of the disk. Such is the case with HD 53143, which was not seen in previous coronagraphic surveys because coronagraphs purposely block a star’s light in order to see nearby objects more clearly. The galaxy may also be home to a second disk and at least one planet.
“Until now, scientists had never seen a debris disk with such a complicated structure. Besides being an ellipse with a star in one focus, it probably also has a second inner disk that is misaligned or tilted relative to the outer one.” disk.” said Meredith MacGregor, an assistant professor at the Center for Astrophysics and Space Astronomy (CASA) and Department of Astrophysical and Planetary Sciences (APS) at CU Boulder, and the study’s lead author. “To produce this structure, there must be a planet or planets in the system that are disrupting the material in the disk by gravity.”
This level of eccentricity, MacGregor said, makes HD 53143 the most eccentric debris disk yet observed, twice as eccentric as the Fomalhaut debris disk, which MacGregor fully imaged at millimeter wavelengths in 2017 using ALMA. “Until now, we don’t have many disks with significant eccentricity. In general, we don’t expect disks to be very eccentric unless something, like a planet, sculpts them and forces them to be eccentric. Without that force, orbits tend to spinning around, as we see in our own solar system.”
Importantly, MacGregor notes that debris disks are not just collections of dust and rocks in space. They are a historical record of planetary formation and how planetary systems evolve over time. and give a glimpse into their future. “We can’t study the formation of the Earth and the solar system directly, but we can study other systems that are similar to but younger than our own. It’s a bit like looking back in time,” she said. “Debris disks are the fossil record of planet formation, and this new result is confirmation that there is much more to learn from these systems and that knowledge can provide glimpses into the complicated dynamics of young galaxies similar to our own solar system.”
dr. Joe Pesce, NSF Program Officer for ALMA, added: “We find planets everywhere we look, and these fantastic results from ALMA show us how planets form — both those around other stars and in our own solar system. This research shows how astronomy works and how progress is being made, informing not only what we know about the field, but also about ourselves.”
#Scientists #hunting #fossils #planetary #formations #reveal #unexpected #eccentricities #nearby #debris #disk #radio #images #shed #light #early #development #Sunlike #systems