Using the Atacama Large Millimeter / submillimeter Array (ALMA), astronomers first imaged the debris disk of nearby star HD 53143 at millimeter wavelengths, and it appears nothing as they expected. Based on early coronary data, scientists expected ALMA to confirm the debris disc as a front ring strewn with piles of dust. Instead, the observations took a surprise turn, revealing the most complicated and eccentric disc of debris observed to date. The observations were presented today in a press conference at the 240th meeting of the American Astronomical Society (AAS) in Pasadena, California, and will be published in an upcoming edition of The letters of the astrophysical diary (ApJL).
HD 53143 – an approximately one billion-year-old Sun-like star located 59.8 light-years from Earth in the constellation Carina – was first observed with the Advanced Camera for Surveys on the Hubble Space Telescope ( HST) coronagrafica in 2006. It is also surrounded by a disk of debris – a belt of comets orbiting a star that constantly collide and crumble into smaller dust and debris – which scientists previously believed was a ring front similar to the disk of debris surrounding our Sun, more commonly known as the Kuiper belt.
The new observations were made of HD 53143 using the highly sensitive Band 6 receivers on ALMA, an observatory cooperated by the US National Science Foundation’s National Radio Astronomy Observatory (NRAO), and revealed that the star system’s debris disk is actually highly eccentric. In ring-shaped discs of debris, the star is typically located in the center of the disc or near it. But in eccentric elliptical discs, the star resides in a focus of the ellipse, away from the center of the disc. This is the case with HD 53143, which has not been seen in previous coronary studies because coronographs purposely block the light from a star to see nearby objects more clearly. The star system could also host a second disk and at least one planet.
“Until now, scientists have never seen a debris disk with such a complicated structure. In addition to being an ellipse with a star in focus, it probably also has a second internal disk that is misaligned or tilted relative to the outer disk.” . said Meredith MacGregor, assistant professor at the Center for Astrophysics and Space Astronomy (CASA) and Department of Astrophysical and Planetary Sciences (APS) at CU Boulder, and the lead author of the study. “To produce this structure, there must be one or more planets in the system that are gravitationally perturbing the material in the disk.”
This level of eccentricity, MacGregor said, makes the HD 53143 the most eccentric debris disc observed to date, being twice as eccentric as the Fomalhaut debris disc, which MacGregor fully imaged at millimeter wavelengths using ALMA. in 2017. “So far, we haven’t found many records with significant eccentricity. In general, we don’t expect records to be very eccentric unless something, like a planet, carves them and forces them to be eccentric. Without that come on, orbits tend to circulate, like what we see in our solar system. “
Importantly, MacGregor notes that debris disks aren’t just collections of dust and rocks in space. They are a historical record of planetary formation and how planetary systems evolve over time. and take a peek into their future. “We can’t study the formation of the Earth and the Solar System directly, but we can study other systems that look similar but younger than ours. It’s kind of like looking back in time,” he said. “The debris discs are the fossil record of planet formation and this new result confirms that there is much more to be learned from these systems and that knowledge can provide a glimpse into the complicated dynamics of young star systems similar to our own. Solar. “
Dr. Joe Pesce, NSF program manager for ALMA, added: “We are finding planets everywhere we look and these fabulous results from ALMA show us how planets are formed, both around other stars and in our own Solar System. demonstrates how astronomy works and how progress is made, informing not only what we know on the ground but also about ourselves. “
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