According to a team of astronomers from the Leibniz Institute for Astrophysics at the University of Potsdam, the XX triangular star, a bright K0 giant star in a binary star system located in the constellation Triangulum, exhibits chaotic, aperiodic star point behavior. That’s what it means. and Konkoli Observatory.
XX A star spot on the surface of the constellation Triangulum. Image credits: HUN-REN RCAES / Zs. Kushvari, MOME / Á. Radovani, AIP / K. Strassmeyer.
“Among the things that can be observed from a spatially resolved solar disk are the number, size and morphology of sunspots, their growth and decay, and their movement in latitude and longitude,” said lead author and director of the Leibniz Institute for Astronomy. said Professor Klaus Strassmeyer. Potsdam Astrophysics and Potsdam University, and their colleagues.
“Such spots are also seen on other stars and are called star spots.”
“We use indirect surface imaging techniques to invert the spectral line profile into an image of the stellar surface.”
“Typically we only get occasional snapshots of spots on a star’s surface, but the spots change systematically over time, and like the Sun, only then can we learn about the internal dynamos and structure of the target in question. Well known.”
“We chose the XX triangular star, one of the most speckled stars in the sky, for a more sustained application of Doppler imaging.”
XX triangle It is located about 640 light years away in the constellation Triangulum.
The star, also known as XX Tri or HD 12545, has a mass only 10% more than the Sun, a radius 10 times the Sun’s radius, and an effective temperature of 4630 K.
It has a rotation period of 24 days, which is synchronized with the orbital period of the binary star system.
XX Trigonum has previously been shown to contain a gigantic star spot with physical dimensions equivalent to 10,000 times the area of the largest group of spots ever seen on the Sun, and 10 times the size of the projected solar disk. It had been discovered in
Professor Strassmeier and his co-authors took 99 separate images of the star using an indirect surface imaging technique called Doppler imaging.
“A dark spot on the star’s surface caused its optical center (a point that essentially represents the star’s ‘center of light’) to shift by up to 24 microarcseconds, which is less than the radius of the star’s visible disk. This corresponds to approximately 10%,” they said. Said.
“These changes occur because the dark spots reduce the brightness of certain areas of the star, shifting the perceived center of light slightly.”
“However, unlike the sun’s predictable activity cycles, the displacements of these photocenters did not follow a periodic pattern. This is a largely chaotic and probably aperiodic pattern, very different from the solar dynamo. This suggests that it is a dynamo.”
“This phenomenon also highlights challenges in detecting exoplanets, as spot-induced fluctuations in the optical center can mimic or mask small movements caused by orbiting planets, which could impose substantial limitations on the detection of such exoplanets by astronomical observations.”
of findings appear in the diary nature communications.
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KG Strassmeyer others. 2024. XX Long-term Doppler images of triangular stars show chaotic aperiodic dynamos. Nat Commune 15, 9986; doi: 10.1038/s41467-024-54329-4
Source: www.sci.news
