Astronomers have detected a previously unobserved eclipse pattern in the four-star system named TIC 433545934 using NASA’s TESS satellite. The “2+2” system consists of two pairs of stars moving in elliptical orbits around their common center of mass. It was observed that the stars in pair B passed in front of the two stars in pair A, creating an eclipse; however, the reverse did not occur.
According to the study, this is the first system in which eclipses have been observed between two pairs of stars. The stars in pair A have masses 2.2 and 2.4 times that of the Sun, while one of the stars in pair B has a mass 1.3 times that of the Sun. The pairs complete their own orbits in two days and 1.4 days, respectively, and complete their common orbit around each other in 224.5 days. The three massive stars in the 580-million-year-old system are expected to fill their Roche lobes and begin transferring matter in approximately 152 million years.
Why it matters
This finding shows that quadruple-star systems should be studied not only by the number of stars they contain, but also by the direction in which the pairs cross in front of one another and by their movement in their common orbit. The fact that the eclipse is observed only when pair B passes in front of pair A provides direct observational data about the system’s geometry and the relative positions of the pairs. This feature makes the system a distinct area of study for astronomers seeking to understand how stars interact with one another and how those interactions may change over time. The expectation that the three massive stars will eventually fill their Roche lobes and begin transferring matter leaves open the question of what consequences the current arrangement will have for stellar evolution.
Background
NASA is not a new name in the FikirPilot archive: over the past 90 days, we have published 7 news stories mentioning it; the most recent is dated August 26, 2026. This development is added alongside those entries in our archive; readers can view the complete timeline by following previous articles bearing the same name in the archive.