According to a statement from the European Southern Observatory (ESO), exozodiacal light may be hiding Earth-like planets in other solar systems from astronomers. Dust created by colliding asteroids mixes with material from slowly evaporating comets and then reflect the light of nearby stars. Astronomers say this creates a glow known as exozodiacal light, which could hinder the discovery of small exo-planets around alien suns.
A team of scientists from the ESO and the University of Grenoble in France have completed a study on exozodiacal light. Group leader Steve Ertel of ESO and the UG reported using the Very Large Telelscope Interferometer in Chile to observe 92 “relatively nearby” stars.
The astronomers found exozodiacal dust around nine of the stars they were studying. A great deal of this dust surrounds older stars. The investigative team was surprised by this because the production of dust should actually slow down as collisions reduce the number of planetesimals in any given star system.
Their data, soon to be published in the journal Astronomy & Astrophysics, revealed that out of the 92 stars they studied 14 host exoplanets. In the 14 star systems, the planets are reportedly located in the same region as the dust in the systems showing exozodiacal light. This could be problematic and hamper future attempts to study such exoplanets in more detail. The scientists say that even low levels of exozodiacal dust can easily obscure Earth-size exoplanets in “direct imaging.”
Olivier Absil, co-author of the study, explained: “The high detection rate found at this bright level suggests that there must be a significant number of systems containing fainter dust, undetectable in our survey, but still much brighter than the solar system’s zodiacal dust. The presence of such dust in so many systems could therefore become an obstacle for future observations, which aim to make direct images of Earth-like exoplanets.”
Ertel concluded: “If we want to study the evolution of Earth-like planets close to the habitable zone, we need to observe the zodiacal dust in this region around other stars. Detecting and characterizing this kind of dust around other stars is a way to study the architecture and evolution of planetary systems.”
Exozodiacal Light Hiding Strange New Worlds