TESS, the Transiting Exoplanet Survey Satellite, has been on the lookout for alien worlds since 2018. It has just hit the news again, having identified an extreme triple star system where two stars orbit each other every 1.8 days. The third component circles them both in 25 days – this puts the entire system within the orbit of Mercury with a little wriggle room to spare! To visual observers, it looks like a single star, but the power of TESS revealed a flicker as the stars line up and pass one another along our line of sight. Eventually, the two inner stars will merge, triggering a supernova event!
Understanding Exoplanets
Exoplanets are planets in orbit around other star systems. Unlike the familiar planets in our own Solar System, their size and composition varies widely. To date, gas giants larger than Jupiter have been found and small rocky worlds similar to Earth have been spotted. The techniques to hunt down alien worlds vary, from the transit method to the radial velocity method, which detects a star’s wobble caused by the presence of a planet.
Launch of TESS
TESS was launched by NASA in April 2018 with the purpose of hunting down exoplanets. It uses a technique that relies upon searching for transit events as planets cross the face of their host star. Since it began operations, TESS has monitored the brightness of over 200,000 stars, looking for tiny dips in brightness. It’s been particularly focused on looking for Earth-sized planets orbiting within a star's habitable zone. Here, the conditions are such that a planet could support liquid water and therefore may harbor life.
The Discovery of TIC 290061484
In an exciting twist to the usual approach for hunting exoplanets, a team of professional and amateur astronomers have joined forces with artificial intelligence and found a strange new multiple star system called TIC 290061484. It consists of twin stars orbiting each other every 1.8 days and a third star that orbits them both in just 25 days. The discovery beats the existing record for the shortest outer orbital period of a stellar system that was set in 1956 by 8 days!
Data Analysis and Findings
The edge-on presentation of the system is perfectly aligned for analysis. Monitoring the movement and brightness changes, it is possible to measure orbits, masses, sizes, and temperatures of the stellar components. The team, led by Veselin Kostov from NASA’s Goddard Space Flight Center, published their findings in the Astrophysical Journal.
Using TESS’ sensitivity to pick up flickering and brightness changes, the nature of the triple star system was revealed. Located in the constellation Cygnus, almost 5,000 light-years away, the team monitored the dips in brightness as one star passed in front of another. Utilizing the capabilities of AI and machine learning, the team was able to filter the immense amounts of data to identify dimming events from transits rather than just the flicking of light caused by our own atmosphere.
The Role of Citizen Scientists
The data was then analyzed by teams of citizen scientists who had formed ‘The Planet Hunters’ in 2010 to support exoplanet surveys. They later joined forces with professional astronomers as ‘the Visual Survey Group’ where they would provide real visual assessment of survey results. The team has now developed the model for the system and even forecasted that, in between 20 to 40 million years, the inner stars will expand and trigger a supernova explosion.
Implications of the Discovery
The hunt is ongoing for more close multiple star systems, with the Nancy Grace Roman Space Telescope (NGRST) joining the effort. With its far higher resolution, NGRST will offer 36,000 pixels where TESS only offered 1, giving a new window on the same region of the Galaxy.
Source: NASA’s TESS Spots Record-Breaking Stellar Triplets
Conclusion
The discovery of TIC 290061484 significantly enhances our understanding of the dynamic nature of star systems and offers new opportunities for future research. As technology advances, our ability to explore and understand the cosmos will undoubtedly expand, leading to more fascinating discoveries in the field of astronomy.
