Some astronomers have a notion that exoplanet searches might not be spotting half of all Earth-sized planets revolving around other stars. The findings hint that exoplanets could be missed in binary star systems that are hidden by the glare of the parent stars. Astronomers note that nearly half of all stars are binary systems, which means a huge number of Earth-sized planets is being overlooked.
Scientists on the project made use of twin telescopes from the Gemini Observatory to determine that several planet-hosting stars observed by NASA’s TESS exoplanet mission are binary pairs with planets orbiting one of the stars in the pair. After examining the binary stars carefully, the team came to a conclusion that Earth-sized planets in many binary star systems could have been overlooked by TESS and other similar systems.
Two stars are mistaken for one
The light from the second star in the binary pair makes it hard for systems to see changes in the light of the host stars as planets pass by. The team first determined a few of the Earth-sized planets that were identified by TESS were actually unidentified binary stars. Sometimes stars in a pair are so close that they can be mistaken for a single star unless observed at extremely high resolution.
The team made use of both Gemini telescopes to observe samples of exoplanet host stars in high resolution, thanks to a technique called speckle imaging. Astronomers observed hundreds of stars that TESS had identified as potential exoplanets. The team found out that 73 of those stars were binary star systems that appeared as single stars unless seen in high detail.
TESS data was used for new findings
Astronomers also observed 18 additional binary star systems that were earlier discovered by TESS and compared the size of detected planets in the binary systems to those in single-star systems.
It was found that the TESS data discovered large and small exoplanets orbiting single stars but only found large planets in binary systems. The scientists believe these results show that many Earth-sized planets may be in binary systems and might have gone unnoticed.
