Astronomers have spotted a pair of stars in a dramatic death spiral, and it’s enhancing our understanding of gravity. Named ZTF J2130, this system is located about 4,000 light-years from Earth. This recent observation offers unprecedented clarity.
The two stars are on a collision course. As they spin closer together, they align with theoretical predictions about gravity, making this system a prime candidate for future testing. A study submitted to the journal Astronomy & Astrophysics highlights their significance.
This system has been around for quite some time. One star is a white dwarf, the hot remnant of a sun-like star, and the other is a subdwarf star, nearing the end of its life cycle. They orbit each other every 40 minutes, their strong mutual gravity distorting their shapes. Material from the subdwarf is streaming onto the white dwarf.
Their rapid movement generates gravitational waves, tiny ripples in space-time first theorized by Albert Einstein. These waves steal energy from the system, drawing the stars closer together over time. As they get nearer, researchers are tracking their orbital period with precision. Each second, their orbit shortens by about two-trillionths of a second.
This finding supports existing theories of gravity. Scientists have been eager for new tests beyond Einstein’s general relativity, which has stood for over a century.
Interestingly, the upcoming Laser Interferometer Space Antenna (LISA) mission, set to launch in the 2030s, aims to directly measure the gravitational waves from this star system. By then, ZTF J2130 will still be in its death spiral, offering a unique chance for measurements.
When these stars finally collide, the explosion could rival a supernova, potentially visible to the naked eye. Until then, we’ll keep our eyes on the skies, eager to see how this cosmic drama unfolds.
For more about gravitational waves and their significance, you can explore publications from the European Space Agency.
