1. A transit timing variation observed for the long-period extremely low-density exoplanet HIP 41378 f
- Author
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J. I. Vines, Chris Stockdale, Samantha Thompson, Michaël Gillon, Sarah L. Casewell, Richard G. West, C. Murray, Akihiko Fukui, Julien de Wit, Stéphane Udry, Rosanna H. Tilbrook, David J. Armstrong, Douglas R. Alves, L. Delrez, Benjamin V. Rackham, Edward M. Bryant, Valerio Nascimbeni, David R. Anderson, Samuel Gill, Matthew R. Burleigh, Enric Palle, Elsa Ducrot, Maximiliano Moyano, P. P. Pedersen, Monika Lendl, Peter J. Wheatley, Molly R. Kosiarek, Michael R. Goad, James S. Jenkins, Thiam-Guan Tan, Brice-Olivier Demory, Jack S. Acton, Amaury H. M. J. Triaud, Daniel Bayliss, Prajwal Niraula, Beth A. Henderson, Tianjun Gan, Norio Narita, Caroline Odden, Bronwen J. Hardee, Alexandre Santerne, Philipp Eigmüller, Maximilian N. Günther, A. Burdanov, D. Sebastian, Benjamin F. Cooke, Supachai Awiphan, Francisco J. Pozuelos, Hannu Parviainen, Emmanuel Jehin, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), University of Warwick [Coventry], Institut d'Optique Graduate School (IOGS), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, National Astronomical Research Institute of Thailand (NARIT), Department of Physics and Astronomy [Leicester], University of Leicester, Cavendish Laboratory, University of Cambridge [UK] (CAM), Center for Space and Habitability (CSH), University of Bern, The University of Tokyo (UTokyo), Instituto de Astrofisica de Canarias (IAC), Space Sciences, Technologies and Astrophysics Research Institute (STAR), Universidad de Chile = University of Chile [Santiago] (UCHILE), Department of Astronomy and Astrophysics [UCSC Santa Cruz], University of California [Santa Cruz] (UC Santa Cruz), University of California (UC)-University of California (UC), Austrian Academy of Sciences (OeAW), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Observatoire Astronomique de l'Université de Genève (ObsGE), and Université de Genève = University of Geneva (UNIGE)
- Subjects
Extrasolare Planeten und Atmosphären ,planets and satellites: detection ,[PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] ,FOS: Physical sciences ,Astrophysics ,01 natural sciences ,techniques: photometric ,Planet ,Long period ,0103 physical sciences ,Low density ,Transit (astronomy) ,10. No inequality ,010303 astronomy & astrophysics ,Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,planets and satellites: individual: HIP 41378 f ,Transit-timing variation ,010308 nuclear & particles physics ,520 Astronomy ,Astronomy and Astrophysics ,Orbital period ,Exoplanet ,Photometry (astronomy) ,13. Climate action ,Space and Planetary Science ,stars: individual: HIP 41378 ,Astrophysics - Earth and Planetary Astrophysics - Abstract
HIP 41378 f is a temperate $9.2\pm0.1 R_{\oplus}$ planet with period of 542.08 days and an extremely low density of $0.09\pm0.02$ g cm$^{-3}$. It transits the bright star HIP 41378 (V=8.93), making it an exciting target for atmospheric characterization including transmission spectroscopy. HIP 41378 was monitored photometrically between the dates of 2019 November 19 and November 28. We detected a transit of HIP 41378 f with NGTS, just the third transit ever detected for this planet, which confirms the orbital period. This is also the first ground-based detection of a transit of HIP 41378 f. Additional ground-based photometry was also obtained and used to constrain the time of the transit. The transit was measured to occur 1.50 hours earlier than predicted. We use an analytic transit timing variation (TTV) model to show the observed TTV can be explained by interactions between HIP 41378 e and HIP 41378 f. Using our TTV model, we predict the epochs of future transits of HIP 41378 f, with derived transit centres of T$_{C,4} = 2459355.087^{+0.031}_{-0.022}$ (May 2021) and T$_{C,5} = 2459897.078^{+0.114}_{-0.060}$ (Nov 2022)., Comment: Accepted for publication in MNRAS Letters. 6 pages, 2 figures
- Published
- 2021
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