James Webb Space Telescope: finally, the edge of the Universe and beyond | UdeMNouvelles

The James Webb Space Telescope has recently made a fascinating discovery: dozens of mysterious “rogue” planets drifting through space, often found in pairs. A new study may shed light on the puzzling nature of these rare “JuMBOs.”

These rogue planets, lacking a parent star, have intrigued astronomers for years. Among them are pairs of Jupiter-sized worlds orbiting each other, a phenomenon known as Jupiter-mass binary objects (JuMBOs). However, the origin of these free-floating planets (FFPs) has remained elusive.

First detected over two decades ago using the United Kingdom Infrared Telescope, FFPs have continued to captivate astronomers’ attention. Last year, the James Webb Space Telescope uncovered over 500 FFPs in the Orion Nebula, with 80 of them forming pairs.

The formation mechanisms of JuMBOs and FFPs have been subjects of speculation. One theory suggests they form from collapsing gas and dust clouds, akin to star formation on a smaller scale. Another posits that they are ejected from their parent planetary systems by gravitational interactions with passing massive objects, like stars.

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To investigate these possibilities, researchers, including Lai and Fangyuan Yu from Shanghai Jiao Tong University, conducted tens of thousands of simulations of planetary systems containing pairs of Jupiter-sized planets orbiting a sun-like star. They found that close initial orbits and higher planet masses increased the likelihood of JuMBO formation.

However, even in the most favorable scenarios, the chances of paired planets being ejected simultaneously were extremely low, less than 1%. In contrast, single planets were much more likely to be ejected during a stellar flyby, resulting in solitary FFPs.

The simulations also revealed that surviving orbiting planets were often significantly perturbed, with their circular paths distorted into elliptical trajectories.

While the research has not yet undergone peer review, it has been submitted to The Astrophysical Journal. Lai and Yu believe their findings support the cloud-collapse model as a probable explanation for JuMBO formation.

Furthermore, their work has practical implications for future astronomical observations, particularly with telescopes like the Vera C. Rubin Observatory. By understanding the dynamics of planetary systems in dense star clusters, researchers can better identify exotic planetary phenomena, including captured planets.