The Apparently Decaying Orbit of WASP-12b
Name
Patra_2017_AJ_154_4.pdf
Size
678.56 KB
Format
Adobe PDF
Checksum (MD5)
35e6b3b7310126801584410d79790abe
Author(s)
Patra, Kishore C.
Winn, Joshua N.
Holman, Matthew J.
Yu, Liang
Deming, Drake
Dai, Fei
Date Issued
June 2017
Journal
Astronomical Journal
Publisher
IOP Publishing
Citation
Patra, Kishore C., Joshua N. Winn, Matthew J. Holman, Liang Yu, Drake Deming, and Fei Dai. “The Apparently Decaying Orbit of WASP-12b.” The Astronomical Journal 154, 1 (June 2017): 4 © 2017 The American Astronomical Society
Version
Final published version
Abstract
We present new transit and occultation times for the hot Jupiter WASP-12b. The data are compatible with a constant period derivative: P = -29 ± 3msyr ⁻¹ and P/P = 3.2 Myr. However, it is difficult to tell whether we have observed orbital decay or a portion of a 14-year apsidal precession cycle. If interpreted as decay, the star's tidal quality parameter All rights reserved. ∗ is about 2 × 10⁵. If interpreted as precession, the planet's Love number is 0.44 ± 0.10. Orbital decay appears to be the more parsimonious model: it is favored by Δx² = 5.5 despite having two fewer free parameters than the precession model. The decay model implies that WASP-12 was discovered within the final ∼0.2% of its existence, which is an unlikely coincidence but harmonizes with independent evidence that the planet is nearing disruption. Precession does not invoke any temporal coincidence, but it does require some mechanism to maintain an eccentricity of ≈0.002 in the face of rapid tidal circularization. To distinguish unequivocally between decay and precession will probably require a few more years of monitoring. Particularly helpful will be occultation timing in 2019 and thereafter.
MIT Department
Massachusetts Institute of Technology. Department of Physics
MIT Kavli Institute for Astrophysics and Space Research
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.3847/1538-3881/aa6d75
