It is probably only a matter of time before the first moon outside our solar system will be confirmed.
We know there are planets outside our solar system. But do these exoplanets actually have exomoons? While that may seem obvious, it is not sure. Researchers now suggest in a new study that they have found an exomoon.
The six potential exomoons– which the researchers reveal in the journal Monthly Notices of the Royal Astronomical Society – are located in the galaxies KOI 268.01, Kepler 517b, Kepler 1000b, Kepler 409b, Kepler 1326b, and Kepler 1442b and are between 200 and 3000 light-years from Earth. The researchers tracked the exomoon holes using data from the late Kepler Space Telescope, which noticed dips in the starlight when an exoplanet moved in front.
However, it is far from easy to reveal an exomoon. “The candidates are so small that we can’t see them through their own induced dips,” explains researcher Paul Wiegert. “The gravity they exert on their mother planet betrays their presence.” When an exoplanet circles its star undisturbed, the starlight is stopped at periodic moments. But sometimes these dips in brightness take place irregularly. Such variations reflect the gravity of another celestial body. And so such an irregular dip can mean that there is an exomoon or other planet in the same system and affects the exoplanet moving.
“Because exoplanets are more massive than exomoons, most of the irregular dips observed so far have been associated with the influence of other exoplanets,” said researcher Chris Fox. “But now we have found six systems in which we can explain the observed irregular dips by exomoons as well as exoplanets. That’s why we’re calling them ‘candidates’ at the moment because they still need to be confirmed.”
Still, the researchers are hopeful. “It could well be that the six systems harbor exomoons,” fox says. “Their masses and orbits are stable and the pattern of irregular dips can be seen throughout the Kepler dataset. However, we do not yet have the right technology to confirm and display the exomoons directly. So we will have to be patient for a while.”
Reference and citations:
” Western Space team theorizes rare exomoon discovery ” – Western University