Half of this strange star’s surface pulsates, creating a unique, teardrop shape.
Key Takeaways
- Amateur astronomers discovered a star with unusual pulsations occurring only on one hemisphere.
- This star is part of a binary system with a red dwarf star, which distorts its shape and pulsations.
- The star’s unique pulsation pattern has been theorized since the 1980s but never observed until now.
- The TESS satellite’s detailed data allowed researchers to observe minute variations in brightness and shape.
- The discovery opens the door to identifying similar stars hidden within TESS data.
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A Half-Pulsating Star with a Teardrop Shape
Astronomers have discovered a unique star, known as HD74423, that pulsates only on one hemisphere, creating an unusual teardrop shape. The star was initially spotted by amateur astronomers analyzing data from NASA’s Transiting Exoplanet Survey Satellite (TESS). The study, published in Nature Astronomy, delves into this extraordinary celestial phenomenon.
HD74423 is located about 1,500 light-years from Earth and is part of a binary star system with a close companion—a red dwarf star. The red dwarf’s gravitational influence distorts the shape of HD74423 and causes its pulsations to occur asymmetrically. Typically, pulsating stars oscillate uniformly, but HD74423 behaves differently, with only one side visibly pulsating.
One of the key features of this star is its distorted shape, akin to a teardrop, rather than the usual spherical shape seen in most stars. Researchers believe this unusual behavior results from the close orbital dynamics between the two stars, with HD74423 zipping around its companion in less than two Earth days.
Using advanced observational tools like the TESS satellite and instruments like ALMA (Atacama Large Millimeter Array), scientists were able to measure fluctuations in brightness and examine the pulsation in greater detail. This revealed how the varying angles of observation affected the visibility of pulsations on different sides of the star.
Implications and Next Steps
This discovery not only provides insight into how binary star systems can distort stellar behavior but also opens up new avenues for identifying other similar half-pulsating stars. Researchers anticipate more such stars may be found hidden within vast datasets like those collected by TESS, contributing to our broader understanding of star formation and behavior.
