Bochinski, J.J., Haswell, C.A., Marsh, T.R. et al. (2 more authors) (2015) Direct evidence for an evolving dust cloud from the exoplanet KIC 12557548 b. Astrophysical Journal Letters, 800 (2). L21. ISSN 2041-8205
Abstract
We present simultaneous multi-color optical photometry using ULTRACAM of the transiting exoplanet KIC 12557548 b (also known as KIC 1255 b). This reveals, for the first time, the color dependence of the transit depth. Our g and z transits are similar in shape to the average Kepler short-cadence profile, and constitute the highest-quality extant coverage of individual transits. Our Night 1 transit depths are 0.85 +/- 0.04% in z; 1.00 +/- 0.03% in g; and 1.1 +/- 0.3% in u. We employ a residual-permutation method to assess the impact of correlated noise on the depth difference between the z and g bands and calculate the significance of the color dependence at 3.2{\sigma}. The Night 1 depths are consistent with dust extinction as observed in the ISM, but require grain sizes comparable to the largest found in the ISM: 0.25-1{\mu}m. This provides direct evidence in favor of this object being a disrupting low-mass rocky planet, feeding a transiting dust cloud. On the remaining four nights of observations the object was in a rare shallow-transit phase. If the grain size in the transiting dust cloud changes as the transit depth changes, the extinction efficiency is expected to change in a wavelength- and composition-dependent way. Observing a change in the wavelength-dependent transit depth would offer an unprecedented opportunity to determine the composition of the disintegrating rocky body KIC 12557548 b. We detected four out-of-transit u band events consistent with stellar flares.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015 American Astronomical Society. This is an author-produced version of a paper subsequently published in Astrophysical Journal Letters. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | dust, extinction; planetary systems; planets and satellites: detection; planets and satellites: individual (KIC-12557548-b); stars: individual (KIC-12557548) |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Funding Information: | Funder Grant number Science and Technology Facilities Council ST/M001350/1; ST/J001589/1; ST/M002012/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 03 Mar 2021 08:49 |
Last Modified: | 03 Mar 2021 10:56 |
Status: | Published |
Publisher: | IOP Publishing |
Refereed: | Yes |
Identification Number: | 10.1088/2041-8205/800/2/L21 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:171518 |