Astronomers have spotted a record-breaking stellar eclipse occurring in a binary star system nearly 10,000 light-years from Earth. Every 69 years the recently discovered system, called TYC 2505-672-1, is covered in darkness for almost 3.5 years. According to a research published in Astronomical Journal, it is both the longest eclipse duration and the longest period between eclipses ever seen. Astronomers say that TYC 2505-672-1 broke the record beforehand held by Epsilon Aurigae, a star that is eclipsed every 27 years for up to 730 days.
TYC 2505-672-1 being 10,000 light-years away from Earth is difficult to observe. Astronomers believe the two stars in the system are red giants - one a primary star, and the other a "stripped" companion star with a quite smaller core bounded by a tremendously large disk of material that may produce the eclipse. This companion star is almost 2000 degrees C hotter than our Sun. In order to explain long interval between eclipses, astronomers think the stars are likely orbiting at a distance of 20 astronomical units (about the distance between the Sun and Uranus).
Astronomer Keivan Stassun says that the star system provides a unique prospect for researchers. Many astronomical phenomena take place so far away and over such a long time that they're hard to detect in a single human lifespan.
But in the case of TYC 2505-672-1, researchers have been able to draw on a century of data gathered by astronomers at Harvard University between 1890 and 1989.
Stassun explains "One of the great challenges in astronomy is that some of the most important phenomena occur on astronomical timescales, yet astronomers are generally limited to much shorter human timescales. Here we have a rare opportunity to study a phenomenon that plays out over many decades and provides a window into the types of environments around stars that could represent planetary building blocks at the very end of a star system's life."