International investigation provides new data to understand the evolution of exoplanets and stellar systems.
An international team of researchers has discovered, for the first time, a planetary nebula that destroyed its solar system but preserved the remains of an exoplanet. The discovery, published in provides new data to understand the evolution of exoplanets and stellar systems.
O (IAC) explained, in a statement released on Wednesday, that so far they have been discovered more than 5,000 exoplanets orbiting stars of all types and of almost all evolutionary stages.
Although exoplanets have been seen around white dwarfs, i.e. the last phase in the life of low and intermediate mass stars like the Sunan exoplanet has never been detected around a star in the previous phase, precisely the one called a planetary nebula.
Planetary nebulae are bright bubbles found around younger white dwarfs, formed from matter ejected from the system’s central star at the end of its life, just before it became a white dwarf.
The expulsion of this matter interferes with the planets orbiting the star, causing the closest ones to fall inland until they are swallowed by the central star, and the less close ones to move even further away, even breaking free and escaping. of that star system.
The absence of exoplanets detected around stars in the planetary nebula phase presents significant problems for understanding how exoplanets can exist around stars in later evolutionary phases.
“This discovery, published in the journal Nature Astronomy, in which the IAC participated, is an important step towards understanding the population of exoplanets around evolved stars”, said the IAC.
Data from 2,000 planetary nebulae
The discovery was made through inspection of data from 2,000 central stars of planetary nebulae from the GAIA satellite and ZTF mapping, which stands for Zwicky Transient Facility, an astronomical observation project that uses robotic telescopes to scan large areas of the night sky regularly and allows changes in it to be studied.
The only viable explanation
It was an amateur astronomer, Klaus Bernhard, belonging to the German association Bundesdeutsche Arbeitsgemeinschaft fur Veranderliche Sterne, who discovered very unusual behavior in one of these planetary nebulae.
“Looking at the data, I noticed that in 2021 the central star of WeSb1 dimmed more than ninety percent for a few weeks and then returned to its normal brightness. In previous years, there were also times when it dimmed a lot, but always with different duration and never becoming so weak”, said Klaus Bernhard.
“The typical indication of the presence of an exoplanet or companion star is short, regular dips in the star’s brightness due to eclipses, so it was a big surprise when Klaus showed us the very rare variability of this star,” explained David Jones, co-author of the paper. and researcher at IAC.
For James Munday, co-author of the article and PhD student at the University of Warwick, in the United Kingdom, the only viable explanation for its behavior is that there were large clouds of dust orbiting close to the central star and within the nebula.
“By bringing together all the data from different sources, it became clear what was happening in the system,” highlighted Jan Budaj, lead author of the study and researcher at the Slovak Academy of Sciences.
Budaj added that “the central star is not one star, but two” and that the interaction of the central star with its companion “formed the nebula and, at the same time, destroyed its planetary system, leaving the remains in the form of large dust clouds orbiting around the companion star.”
