NASA’s TESS Uncovers Triple Star System with Shortest Known Orbit

Astronomers have identified a new triple star system that has set a record for the shortest orbital period ever observed. The system, designated TIC 290061484, was discovered using data from NASA's Transiting Exoplanet Survey Satellite (TESS), with the help of artificial intelligence and a collaboration between professional and amateur astronomers. This discovery marks a significant breakthrough in understanding the dynamics of multi-star systems.

The Record-Breaking Stellar Trio

The newly discovered system consists of two stars that orbit each other in just 1.8 days, while a third star orbits this inner pair every 25 days. This outer orbit breaks the previous record for the shortest period in a triple star system, which was set in 1956 with an orbital period of 33 days. The system is located in the constellation Cygnus, and its unique configuration allowed scientists to make detailed measurements of the stars' orbits, masses, and temperatures.

Veselin Kostov, a research scientist at NASA's Goddard Space Flight Center and the SETI Institute, emphasized the significance of this discovery: "Thanks to the compact, edge-on configuration of the system, we can measure the orbits, masses, sizes, and temperatures of its stars. And we can study how the system formed and predict how it may evolve." The tight configuration of the stars, where all orbits fit within a space smaller than Mercury's orbit around the sun, suggests the system is remarkably stable, with little interference from each star’s gravity.

Discovering the System Through Cosmic “Strobe Lights”

The discovery of TIC 290061484 was made possible by analyzing "flickers" or dimming in the starlight, known as eclipses, where one star passes in front of another, blocking some of the light. The TESS data, with its ability to monitor brightness changes in stars, enabled astronomers to detect these eclipses and identify this rare system. Machine learning algorithms sifted through vast amounts of data to pick up the patterns, but human input was also essential. A group of citizen scientists, using years of experience, worked alongside professionals to narrow down the most interesting cases.

These volunteers, many of whom previously participated in a Planet Hunters project, are co-authors on the study. According to Saul Rappaport, an emeritus professor of physics at MIT and co-author of the study, "It’s exciting to identify a system like this because they’re rarely found, but they may be more common than current tallies suggest." The system's almost perfectly flat orbital plane from our perspective allowed scientists to observe the stars’ eclipses with exceptional clarity.

The Future of Triple Star System Research

This discovery opens the door to further exploration of triple star systems, particularly ones with even shorter outer orbital periods. The upcoming Nancy Grace Roman Space Telescope, set to launch in the coming years, is expected to provide even more detailed images of star systems. With 36,000 pixels per area—compared to a single pixel with TESS—the Roman telescope will allow astronomers to pierce deeper into the dense regions of our galaxy, potentially revealing more complex systems.

Brian Powell, a data scientist at NASA’s Goddard Space Flight Center, explained the potential of future discoveries: "We don’t know much about a lot of the stars in the center of the galaxy except for the brightest ones. Roman’s high-resolution view will help us measure light from stars that usually blur together, providing the best look yet at the nature of star systems in our galaxy."

While this specific system may not be suitable for hosting planets due to the gravitational forces between its stars, it offers invaluable insights into the formation and evolution of multi-star systems. As the inner pair of stars ages, scientists predict that they will eventually merge, possibly triggering a supernova in the next 20 to 40 million years. However, the system will remain stable for millions of years, allowing astronomers to continue studying its unique properties.