Constraints on the circumstellar dust around KIC 8462852

Abstract

We present millimetre (SMA) and sub-millimetre (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 $\mu$m and are the deepest millimetre and sub-millimetre 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${}_{\oplus }$ and 10${}^{-3}$ M${}_{\oplus }$ for regions identified as the most likely to host occluding dust clumps and a total overall dust budget of $<$7.7 M${}_{\oplus }$ within a radius of 200 AU. Such low limits for the inner system make the catastrophic planetary disruption hypothesis unlikely. Integrating over the Kepler lightcurve we determine that at least 10${}^{-9}$ M${}_{\oplus }$ 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 $\sim$ 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.

6 pages, 4 figures. Some figure resolutions reduced for file size limits. Submitted to MNRAS 11th December 2015

References in corpus (6)

• Astrophysics Source Code Library
• SCUBA-2: iterative map-making with the Sub-Millimetre User Reduction Facility
• Molecular Gas Clumps from the Destruction of Icy Bodies in the $\beta$ Pictoris Debris Disk
• FellWalker - a Clump Identification Algorithm
• KIC 8462852 - The Infrared Flux
• IRTF/SPEX Observations of the Unusual Kepler Lightcurve System KIC8462852

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• On the Nature and Types of Anomalies: A Review of Deviations in Data
• KIC 8462852: Transit of a Large Comet Family
• Tidal disruption of planetary bodies by white dwarfs II: Debris disc structure and ejected interstellar asteroids
• Families of Plausible Solutions to the Puzzle of Boyajian's Star
• The First Post-Kepler Brightness Dips of KIC 8462852
• KIC 8462852 Faded at an Average Rate of 0.165+-0.013 Magnitudes Per Century From 1890 To 1989
• KIC 8462852 Faded Throughout the Kepler Mission
• Modelling the KIC8462852 light curves: compatibility of the dips and secular dimming with an exocomet interpretation
• Secular Dimming of KIC 8462852 Following its Consumption of a Planet
• Mysterious eclipses in the light-curve of KIC8462852: a possible explanation
• Extinction and the Dimming of KIC 8462852
• Photometric and astrometric vagaries of the enigma star KIC 8462852
• Detection of a repeated transit signature in the light curve of the enigma star KIC 8462852: a 928-day period?
• Where Is the Flux Going? The Long-Term Photometric Variability of Boyajian's Star
• Sonneberg plate photometry for Boyajian's Star in two passbands
• The GALEX View of "Boyajian's Star" (KIC 8462852)
• Boyajian's Star B: The co-moving stellar companion to KIC 8462852
• The High Rate of the Boyajian's Star Anomaly as a Phenomenon
• Non-gray, Month-long Brightening of KIC 8462852 in the Immediate Aftermath of a Deep Dip
• High-resolution spectroscopy of Boyajian's star during optical dimming events
• Optical Polarimetry of KIC 8462852 in May-August 2017
• Extrasolar enigmas: from disintegrating exoplanets to exoasteroids