Probing Oort clouds around Milky Way stars with CMB surveys

Understand

Long-period comets observed in our solar system are believed to originate from the Oort cloud, which is estimated to extend from roughly a few thousand to $10^5$ AU from the Sun.

• Despite many theoretical arguments for its existence, no direct observations of the cloud have been reported.
• Here, we explore the possibility of measuring Oort clouds around other stars through their emission at submillimeter wavelengths.
• Observations with the 545 and 857 GHz bands of the Planck satellite are well matched to the expected temperatures of Oort cloud bodies (on the order of 10 K).