Are we missing other Earths? A team of scientists from the International Gemini Observatory and the 3.5-meter WIYN Telescope at the Kitt Peak National Observatory suggests in their new work that Earth-sized worlds may be hidden behind the glow of their parent stars in binary star systems that we cannot detect. We seem to have been missing nearly half of the nearby Earth-sized planets, because about half of all stars are in binary systems.
Earth-sized planets may be much more common than we previously thought. Obviously, size is not the only factor that affects the habitability of a world, which is what we are looking for, some other planet capable of supporting life. Its orbital characteristics or the hostile nature of its parent star could be major impediments to supporting it . However, finding a world similar in size and composition to Earth is considered a promising place to start and, of course, worthy of further observations.
They don’t ‘paint’ the whole picture
But planet-seeking space telescopes like Kepler and TESS more easily detect large worlds than small worlds, so the sample is, according to the new data, even more skewed than we thought, since these telescopes often miss planets the size Earth in binary star systems.
“With the 8.1-meter telescopes at the Gemini Observatory, we obtained very high-resolution images of exoplanet host stars and detected stellar companions at very small separations,” says Kathryn Lester of NASA’s Ames Research Center, who led the team. to locate star companions missed in previous observations.
Using the twin Gemini telescopes and a program from NSF’s NOIRLab they determined that many stars that host planets identified by NASA’s TESS exoplanet hunting mission are actually pairs of stars, whose Earth-sized planets in many systems Two stars could go unnoticed using the transit search method, which looks for changes in a star’s light when a planet passes in front of it. Being a binary system, the light from the second star makes it more difficult to detect changes in the light from the host star as the planet transits.
“We have shown that it is more difficult to find Earth-sized planets in binary systems because small planets are lost in the glow of their two parent stars,” Lester said.
“Its transits are ‘filled in’ by light from the companion star ,” adds Steve Howell of NASA’s Ames Research Center.
The researchers also found that binary stars orbiting a greater degree of separation were more likely to host exoplanets than those in the TESS catalog that were observed orbiting extremely close to each other. This suggests that the turbulent regions of space surrounding the closest orbiting stars are inhospitable for planet formation.
There are many planets similar to Earth but, for now, too difficult to see.
Referencia: Speckle Observations of TESS Exoplanet Host Stars. II. Stellar Companions at 1-1000 AU and Implications for Small Planet Detection, arXiv:2106.13354 [astro-ph.SR] arxiv.org/abs/2106.13354
