According tomedia, the light emitted by stars is not stable, but instead they tend to pulsate. But this usually happens to a star that is evenly on the surface, and now astronomers have discovered a special kind of star, where pulses occur only on one side — thanks to its teardrop shape.
The star, known as HD74423, is about 1.7 times the mass of the sun and is about 1,500 light-years from Earth. There it is not a lonely planet — there is a red dwarf star and two stars orbiting each other (no more than two days).
This tight orbit produced a gravitational pull between the two stars, pulling HD74423 into a teardrop. This seems to allow the larger star to pulsate in an unexpected way.
Zhao Guo, one of the study’s authors, said: “In astronomy, pulsating stars have long been known. The surface of young and old stars with rhythmic pulsations may have long, short, intensity, and causes of formation. So far, however, all of these stars have one thing in common: their pulsations can be seen in all directions of the star. “
But the HD74423 is not – it seems to pulsate only on one side. Astronomers discovered this when they noticed that the spikes and troughs of the pulse were exactly the same as the star’s rotation time.
The researchers say the observation of the phenomenon is based on decades of hypothesis. As early as the 1940s, it was suggested that a companion star close to a star could affect a star’s pulse timing, and the idea of pushing the pulse to a hemisphere has been around since the 1980s. But now the study marks the first time it has been looked directly, and the team says it is likely to be a common astronomical phenomenon.
The study was published in Nature Astronomy.