Mysterious happenings around the star KIC 846852 May 16, 2016 Please Register or Log in to view the hidden image! The Kepler satellite was designed to search for Earth-sized planets in the habitable zone of stars by measuring dips in a star's brightness as orbiting planets move across the stellar disc (transits). Its sensitive camera stares at more than 150,000 stars towards the constellations of Cygnus and Lyrae, and so far has found over 5000 exoplanet candidates. But Kepler also monitors the light fluctuations in all the other stars, even dips not caused by transits, and has found some bizarre situations. Perhaps the strangest is the case of KIC 846852, an otherwise normal star slightly larger than the Sun that has exhibited significant, irregular dips in the flux that last as short as a few days or as long as eighty days, and are as deep as 20%. The source is so far unique in the Kepler database. The irregular and extreme nature of the episodes excludes planetary transits, and other suggestions have ranged from a catastrophic collision between planets that released a cloud of obscuring debris, to the presence of a huge alien artifact like a so-called "Dyson sphere!" Read more at: http://phys.org/news/2016-05-mysterious-star-kic.html#jCp
http://mnrasl.oxfordjournals.org/content/458/1/L39 Constraints on the circumstellar dust around KIC 8462852 Abstract We present millimetre (Submillimeter Array) and submillimetre (SCUBA-2) continuum observations of the peculiar star KIC 8462852 which displayed several deep and aperiodic dips in brightness during the Kepler mission. Our observations are approximately confusion-limited at 850 μm and are the deepest millimetre and submillimetre photometry of the star that has yet been carried out. No significant emission is detected towards KIC 8462852. We determine upper limits for dust between a few 10−6 M⊕ and 10−3 M⊕ for regions identified as the most likely to host occluding dust clumps and a total overall dust budget of <7.7 M⊕ within a radius of 200 au. Such low limits for the inner system make the catastrophic planetary disruption hypothesis unlikely. Integrating over the Kepler light curve we determine that at least 10−9 M⊕ of dust is required to cause the observed Q16 dip. This is consistent with the currently most favoured cometary breakup hypothesis, but nevertheless implies the complete breakup of ∼30 Comet 1/P Halley type objects. Finally, in the wide SCUBA-2 field of view we identify another candidate debris disc system that is potentially the largest yet discovered.
