An international team of astronomers has identified the first rhythm variable stars like Delta Shield — giant stars that dramatically change in brightness due to different types of pulsations on its surface. Article researchers, revealing the secret of the unusual space objects, published in the journal Nature.

The researchers analyzed data about the brightness of thousands of stars obtained using the space telescope TESS (Transiting Exoplanet Survey Satellite), which are mainly used to search for exoplanets around the nearest to the Sun stars. Interest was stars, related to the type of the Delta Shield, which is named in honor of the same stars with the same characteristics. These luminaries about 1.5-2.5 times greater than the Sun, and their pulsations, astronomers have still not found any patterns.

The researchers used a library of open source Lightkurve written in Python, for the treatment of 92 of thousands of light curves, showing how the magnitude of the star changes with time. The result has been to detect high-frequency fashion in the 60 stars like Delta Shield, located at a distance of from 60 to 1400 light-years from Earth.

Delta Shield (δ Scuti) is a multiple system consisting of three stars, the most massive of them — δ of the Shield is a yellow-white giant and changes brightness every 4.6 hours. Similar properties have other stars, including beta Leo and beta Cassiopeia. These stars not only expand and contract, maintaining a spherical shape (radial pulsation), but also occasionally become elongated (predelnye ripple) that zahumlje rhythm changes in brightness.