2017/09/06 by Flavien Kiefer, F. Kiefer, Alain Lecavelier des Etangs +9 · 23 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Brightness #Flux (metallurgy) #Light curve #Orbital period #Star (game theory) #Starspot #Stellar, planetary, and galactic studies #Transit (satellite) #astro-ph.EP
paper · pdf · doi:10.1051/0004-6361/201731306
published in Astronomy and Astrophysics 608, A132 (EDP Sciences)
arxiv created 2017/09/06 · openalex created_date 2017/09/15 · openalex publication_date 2017/09/19 · arxiv updated 2017/12/20 · openalex updated_date 2026/08/06
As revealed by its peculiar Kepler light curve, the enigmatic star KIC 8462852 undergoes short and deep flux dimmings at a priori unrelated epochs. This star presents nonetheless all other characteristics of a quiet 1 Gyr old F3V star. These dimmings resemble the absorption features expected for the transit of dust cometary tails. The exocomet scenario is therefore most commonly advocated. We reanalysed the Kepler data and extracted a new high-quality light curve to allow for the search of shallow signatures of single or a few exocomets. We discovered that among the 22 flux dimming events that we identified, two events present a striking similarity. These events occurred 928.25 days apart and lasted for 4.4 days with a drop in the star brightness by 1000 ppm. We show that the light curve of these events is well explained by the occultation of the star by a giant ring system or by the transit of a string of half a dozen exocomets with a typical dust production rate of 10 5 –10 6 kg s -1 . Assuming that these two similar events are related to the transit of the same object, we derive a period of 928.25 days. The following transit was expected in March 2017 but bad weather prohibited us from detecting it from ground-based spectroscopy. We predict that the next event will occur between 3−8 October 2019.