This star, named HD 53143 , is a billion years old and was first observed in 2006 with the Advanced Camera for Surveys (ACS) on the NASA/ESA Hubble Space Telescope. The star is surrounded by a debris disk that astronomers previously believed to be a frontal ring similar to the debris disk that surrounds our Sun, which we know as the Kuiper Belt.
However, thanks to new observations made by astronomers with the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, experts have been able to verify that HD 53143’s debris disk is actually very eccentric.
“In ring-shaped debris disks, the star is usually at or near the center of the disk,” explained astronomer Meredith MacGregor of the University of Colorado at Boulder and colleagues. “But in elliptically shaped eccentric disks, the star resides at one focus of the ellipse, away from the center of the disk.”
And there could be more
According to the team, HD 53143 may also host a second disk and at least one exoplanet.
“Until now, scientists have never seen a debris disk with such a complicated structure. In addition to being an ellipse with a star at one focus, it also likely has a second inner disk that is misaligned or tilted relative to the outer disk. To produce this structure, there must be a planet or planets in the system that are gravitationally perturbing the material in the disk,” says MacGregor in his study published in the Astrophysical Journal Letters.
This finding makes this star’s debris disk the most eccentric observed to date: it is twice as eccentric as the debris disk around Fomalhaut.
“So far, we haven’t found many disks with significant eccentricity. In general, we don’t expect disks to be very eccentric unless something, like a planet, is sculpting them and forcing them to be eccentric. Without that force, the orbits tend to become circular, like what we see in our own solar system,” concludes MacGregor.
Reference: Meredith A. MacGregor et al. 2022. ALMA Images the Eccentric HD 53143 Debris Disk. ApJL, in press; arXiv: 2206.05856 ALMA / ESO / NAOJ / NRAO / M. MacGregor, University of Colorado, Boulder / S. Dagnello, NRAO, AUI & NSF.
