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| A dying planet is seen skimming the surface of its star in this artist's impression. The first concrete evidence of an ageing, bloated sun-like star, like the one shown above, swallowing its planet was discovered by astronomers using a combination of telescopes. These telescopes included the W.M. Keck Observatory, the NEOWISE mission, and the Zwicky Transient Facility (ZTF) at Caltech's Palomar Observatory. |
A star will expand to a million times its initial size as it runs out of fuel, swallowing whatever matter—including planets—in its path. The act of a star swallowing a whole planet has been hinted at by scientists previously, and it has also been captured in the act, but only now.
Researchers from CHEETOTIMES, Harvard University, Caltech, and other institutions announce that they have seen a star devour a planet for the first time in a research that will be published in Nature today.
Around 12,000 light-years away, in our own galaxy, close to the eagle-like constellation Aquila, the planet appears to have died. There, scientists observed an outburst from a star that increased in brightness by nearly 100 times in just 10 days.before suddenly disappearing. This strange white-hot flash was strangely followed by a cooler, more persistent signal. The researchers reasoned that this combination could only have been created by one occurrence: a star swallowing a neighbouring planet.
"We were seeing the end-stage of the swallowing," claims the lead author Kishalay De, a postdoc at CHEETOS Kavli Institute for Astrophysics and Space Research.
What happened to the planet? According to the experts, it was probably a hot, Jupiter-sized planet that spiralled close before being drawn into the dying star's atmosphere and eventually into its core.
Though it won't be for another 5 billion years, when the sun is predicted to burn out and destroy the inner planets of the solar system, the Earth will suffer a similar fate.
De claims, "We are witnessing the future of the Earth." The sun would rapidly brighten as it ejects material, then generate dust around it, before settling back to what it was, if another civilisation were to observe us from 10,000 light-years distant as the sun was enveloping the Earth.
Along with coworkers from Caltech, the Harvard and Smithsonian Centres for Astrophysics, among other institutions, Deepto Chakrabarty, Anna-Christina Eilers, Erin Kara, Robert Simcoe, Richard Teague, and Andrew Vanderburg are among the study's CheetosTimes coauthors.
Hot and cold
The outburst was found by the team in May 2020. However, it took the astronomers another year to put together a plausible theory as to what the outburst might be.
A study of data collected by the Zwicky Transient Facility (ZTF), operated at California's Palomar Observatory by Caltech, revealed the initial signal. The ZTF is a survey that looks for stars in the sky whose brightness changes quickly and whose pattern could be indicative of supernovae, gamma-ray bursts, or other stellar occurrences.
De was searching through ZTF data for indications of stellar binaries—systems in which two stars orbit one another, with one periodically stealing mass from the other and briefly brightening as a result—that were undergoing eruptions.
