Dust cloud, tail could explain exoplanet’s odd light pattern

This artist's illustration of the unconfirmed exoplanet KIC 12557548 b shows it transiting its star. Some astronomers now think the planet could have a cloud of dust enveloping it along with a cometlike tail, shown in this image.

JPL-Caltech/NASA

Exoplanet candidate KIC 12557548 b may be disintegrating, ejecting dust from its surface that creates an opaque cloud that encircles the planet and a cometlike tail that trails it.

Researchers first reported odd observations of the unconfirmed exoplanet, which sits 1,500 light-years from Earth in the direction of the constellation Cygnus, in 2012. The planet orbits its star in a little more than 15 hours. New Kepler spacecraft data show that for roughly 30 passes in front of its star, the suspected planet blocks less than 0.1 percent of the light from its parent star. On a few passes, the planet blocks more than 0.5 percent of the light, and then it passes without blocking any light at all. Exoplanets studied with this light-shielding, or transit, method usually block the same amount of light on each pass in front of their parent star. 

A tail along with a disk-shaped envelope of dust encircling KIC 12557548 b could explain the planet’s unusual light-blocking patterns, astronomers report November 22 on arXiv.org. The paper has been accepted for publication in Astronomy & Astrophysics.

Ashley Yeager is the associate news editor at Science News. She has worked at The Scientist, the Simons Foundation, Duke University and the W.M. Keck Observatory, and was the web producer for Science News from 2013 to 2015. She has a bachelor’s degree in journalism from the University of Tennessee, Knoxville, and a master’s degree in science writing from MIT.