A New Planetary Architecture: Hot Earths

This is an excerpt from my post on Astrobites:

Title:  A population of planetary systems characterized by short-period, Earth-sized planets
Authors: Jason H. Steffen and Jeffrey L. Coughlin
First Author’s Institution: University of Nevada, Las Vegas
Status: Published in the Proceedings of the National Academy of Sciences (PNAS)

The Kepler space telescope has discovered just over 2500 exoplanets to date, which is more than 70% of all exoplanets found so far.  It has discovered planets and systems vastly different from what we see in our own solar system, such as Super Earths and tightly packed planetary systems.  While both of these are quite easy to visually recognize in the data, other types of systems might not be so apparently obvious.  The authors of this paper claim to discover one such hidden planetary architecture: a population of systems whose main signature is having a short-period (~1 day), Earth-sized planet.