A reanalysis of data from the Kepler telescope has revealed two exoplanets in a system that was previously thought to be empty. They orbit their star in a unique style reminiscent of an old-fashioned merry-go-round.
More than ten years ago, the Kepler telescope conducted a series of observations of the star KOI-134. It managed to detect a series of changes in its brightness, but they occurred at different intervals. As a result, they were filtered out by the automatic system as false positives before the observation results could be analyzed in more detail.
However, thanks to NASA’s practice of making scientific data publicly available, this system got a second chance. In a new study, scientists reanalyzed Kepler’s data on KOI-134 and found that the “false positive” was actually real.
The “false positive” exoplanet has been designated KOI-134 b. It is a so-called warm Jupiter. Its transits are delayed or ahead by up to 20 hours, which is a significant deviation. Because of this, its existence could not be confirmed at the time. The transit delays of KOI-134 b are due to its exposure to the gravity of another exoplanet in this system, named KOI-134 c. It is slightly smaller than Saturn and is located closer to its star than KOI-134 b.
KOI-134 c had previously escaped observation because its orbit lies in a plane different from that of KOI-134 b, and this inclined orbit prevents the exoplanet from passing in front of its star. The orbital planes of these exoplanets differ from each other by approximately 15 degrees, which is a significant indicator. Due to gravitational attraction and repulsion between these two exoplanets, their orbital planes also tilt forward and backward. Researchers figuratively compare them to two wooden ponies bobbing up and down as they circle around on an old-fashioned merry-go-round.
Another interesting feature of the system is a phenomenon called resonance. The two exoplanets are in a 2:1 resonance, which means that while the first exoplanet takes one orbit around the star, the other manages to complete two orbits. In this case, KOI-134 b has an orbital period of about 67 days, while KOI-134 c completes one orbit every 33–34 days.
The discovery once again points out how diverse star system configurations can be. As of today, KOI-134 is the first compact multi-planet system discovered by astronomers with a similar mutual inclination of orbital planes. The discovery also serves as a reminder of the importance of reanalyzing old data using new methods and techniques.
Earlier, we reported on how the Cheops telescope discovered a suicidal exoplanet.
According to NASA
