Even schoolchildren know that the vast majority of stars in the universe have a spherical shape. Refuting all the usual rules of physics, a star, called HD74423, recently discovered in 1500 light years from Earth, has a strange droplet or tear shape. The unusual star is part of a binary system with a red dwarf, which, researchers say, can be the very cause of the curved shape and unusual pulsations. How exactly does a small star affect its larger neighbor?
The strangest star in the universe
Pulsating stars are one of the most unusual stars in the Universe, which periodically increase and decrease in size, while changing their brightness for a relatively short period. Pulsating only in certain parts along strong magnetic fields, these stars for a long time remained one of the most mysterious stars in the Universe, the portal newsweek.com reports.
The most unusual star in the Universe was discovered using the TESS telescope, a recognized exoplanet hunter who managed to find several hundred interesting objects outside the solar system. HD74423, whose mass is approximately 1.7 times the mass of our Sun, is part of a red dwarf binary system. These two stars rotate around each other every 1.6 days, which indicates the closest cosmic distance available between the stars. The gravitational attraction acting on each of the stars distorts them, causing the larger and hotter HD74423 to stretch in the shape of a drop.
The point of the star, the most prone to stretching, pulsates on the very side that faces the satellite. In addition, Simon Murphy from the University of Sydney also noticed that the star HD74423 has some unusual physical properties. In particular, the density, pressure, and gravity indices of individual regions of the star are significantly different from similar indices of neighboring zones of a discovered unique object.
Although the exact reasons for the very unusual behavior of the star remain unclear today, several computer simulations have been carried out that previously showed that the star pulsates along its tidal axis. According to researchers, this may mean that the pulsations can grow to even greater amplitudes, compared with those that were previously observed. Although the part of HD74423, which is opposite from its satellite, has stronger gravity, which allows the star to maintain its usual shape from at least one of the sides, ripples can be seen on it.
Despite the fact that an unusual star may seem truly unique in its kind, researchers believe that in the Universe there are already analogues of the elongated drop-shaped HD74423. So, earlier TESS was able to detect a similar star with a metal shell, whose radiation of light lifts molten metals from the surface into the atmosphere.
Although mankind has already made some progress in the study of objects located in the relative cosmic neighborhood from us, the Universe certainly has even more amazing phenomena that we have yet to discover. However, those grains that we have already been able to find in the vastness of our universe can amaze even the most confident skeptic, which is once again proved by the star HD74423 and its small red satellite.