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TESS Revisits WASP-12: Updated Orbital Decay Rate and Constraints on Atmospheric Variability

Wong, Ian and Shporer, Avi and Vissapragada, Shreyas and Greklek-McKeon, Michael and Knutson, Heather A. and Winn, Joshua N. and Benneke, Björn (2022) TESS Revisits WASP-12: Updated Orbital Decay Rate and Constraints on Atmospheric Variability. Astronomical Journal, 163 (4). Art. No. 175. ISSN 1538-3881. doi:10.3847/1538-3881/ac5680.

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After observing WASP-12 in the second year of the primary mission, the Transiting Exoplanet Survey Satellite (TESS) revisited the system in late 2021 during its extended mission. In this paper, we incorporate the new TESS photometry into a reanalysis of the transits, secondary eclipses, and phase curve. We also present a new Ks-band occultation observation of WASP-12b obtained with the Palomar/Wide-field Infrared Camera instrument. The latest TESS photometry spans three consecutive months, quadrupling the total length of the TESS WASP-12 light curve and extending the overall time baseline by almost two years. Based on the full set of available transit and occultation timings, we find that the orbital period is shrinking at a rate of −29.81 ± 0.94 ms yr⁻¹. The additional data also increase the measurement precision of the transit depth, orbital parameters, and phase-curve amplitudes. We obtain a secondary eclipse depth of 466 ± 35 ppm, a 2σ upper limit on the nightside brightness of 70 ppm, and a marginal 6 2 ± 2 8 eastward offset between the dayside hotspot and the substellar point. The voluminous TESS data set allows us to assess the level of atmospheric variability on timescales of days, months, and years. We do not detect any statistically significant modulations in the secondary eclipse depth or day–night brightness contrast. Likewise, our measured K_s-band occultation depth of 2810 ± 390 ppm is consistent with most ∼2.2 μm observations in the literature.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Wong, Ian0000-0001-9665-8429
Shporer, Avi0000-0002-1836-3120
Vissapragada, Shreyas0000-0003-2527-1475
Greklek-McKeon, Michael0000-0002-0371-1647
Knutson, Heather A.0000-0002-0822-3095
Winn, Joshua N.0000-0002-4265-047X
Benneke, Björn0000-0001-5578-1498
Additional Information:© 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2022 January 20; revised 2022 February 14; accepted 2022 February 16; published 2022 March 17. Funding for the TESS mission is provided by NASA's Science Mission directorate. This paper includes data collected by the TESS mission, which are publicly available from the Mikulski Archive for Space Telescopes. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. We thank the Palomar Observatory team, particularly Paul Nied, Carolyn Heffner, and Tom Barlow, for enabling the K_s-band secondary eclipse observations and facilitating remote operations on the Hale 200" Telescope. I.W. is supported by an appointment to the NASA Postdoctoral Program at the NASA Goddard Space Flight Center, administered by the Universities Space Research Association under contract with NASA. S.V. is supported by an NSF Graduate Research Fellowship. H.A.K. acknowledges support from NSF CAREER grant 1555095. Facilities: TESS - , Palomar/WIRC. - Software: batman (Kreidberg 2015), emcee (Foreman-Mackey et al. 2013), exoplanet (Foreman-Mackey et al. 2021), ExoTEP (Benneke et al. 2019; Wong et al. 2020a).
Funding AgencyGrant Number
NASA Postdoctoral ProgramUNSPECIFIED
NSF Graduate Research FellowshipUNSPECIFIED
Subject Keywords:Hot Jupiters; Exoplanet astronomy; Transit photometry
Issue or Number:4
Classification Code:Unified Astronomy Thesaurus concepts: Hot Jupiters (753); Exoplanet astronomy (486); Transit photometry (1709)
Record Number:CaltechAUTHORS:20220228-183227487
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Official Citation:Ian Wong et al 2022 AJ 163 175
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:113638
Deposited By: George Porter
Deposited On:01 Mar 2022 22:39
Last Modified:25 Mar 2022 21:23

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