The mystery of the Nu Octantis system revealed: a rebellious planet that orbit between two stars

The mystery of the Nu Octantis system revealed: a rebellious planet that orbit between two stars

By Dr. Kyle Muller

The Nu Octantis system is made up of a planet and a star that both orbit around a second star, but in opposite directions.

After more than twenty years of analysis and debates, an international team of astronomers made clarity on one of the strangest star systems ever observed: Nu Octantis. The researchers confirmed that it is not a couple of stars in mutual orbit, but of a Trio complex in which a planet with out of the ordinary characteristics is hidden.

History. It all began in 2004, when David Ramm of the University of Canterbury, New Zealand, noted a anomalous signal from Nu Octanis. The signal seemed to indicate the presence of a planet of double size Compared to Jupiter.

But the hypothesis was accepted with skepticism: the two stars of the system are so close as to make the survival of a stable planet in their vicinity theoretically impossible. Yet RAMM – together with Man Hoi Lee of the University of Hong Kong and other colleagues – has now provided the most solid proof ever collected that That signal was not a mistake And it was published in Nature: the planet really exists and His orbit is as unlikely as it is fascinating.

Retrograde motion. The key discovery lies in the retrograde nature of the orbit of the planet: while one of the stars and the planet orbit around the second star, it they do in opposite directions. The planet also follows a much closer orbit, which leads him to pass repeatedly through the narrow space between the two stars.

“It is a rare configuration, but this orbital reversal guarantees the stability of the system,” explains Lee. The confirmation came thanks to the use of advanced tools such as Harps spectrogrademounted on the 3.6 -meter telescope of the Southern European Observatory in Chile, which allowed unprecedented precision observations. The planet’s signal, observed constantly for almost twenty years, also excluded the hypothesis that it was an illusion caused by star activities. “If it had been just noise or a temporary variation, it would have disappeared over time,” underlines Lee.

A past still to be deciphered. But the surprises don’t end there. Thanks to the Very Large Telescope always of the Southern European Observatory, scientists have discovered that one of the stars of the system is a white dwarf, or the collapsed nucleus of a star that came at the end of its life cycle. This information further complicates the reconstruction of the history of the system.

According to mathematical models, the current orbit of the planet would not have been possible when the star was still young and massive.

Two scenarios therefore emerge as plausible: either the planet has radically modified its orbit after the transformation of the star into white dwarf, or it has formed from scratch from the star debris expelled during that process.

Ribelle system. The Nu Octantis system represents a real anomaly compared to the ordered patterns of our Solar Systemin which all the planets orbit in the same direction around a single star. As Manfred Cuntz of the University of Texas in Arlington observes: “Nu Octantis forces scientists to review traditional theories on the formation and evolution of planetary systems”.

Kyle Muller
About the author
Dr. Kyle Muller
Dr. Kyle Mueller is a Research Analyst at the Harris County Juvenile Probation Department in Houston, Texas. He earned his Ph.D. in Criminal Justice from Texas State University in 2019, where his dissertation was supervised by Dr. Scott Bowman. Dr. Mueller's research focuses on juvenile justice policies and evidence-based interventions aimed at reducing recidivism among youth offenders. His work has been instrumental in shaping data-driven strategies within the juvenile justice system, emphasizing rehabilitation and community engagement.
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