Transit timing variations in the WASP-4 planetary system
Abstract
Transits in the planetary system WASP-4 were recently found to occur 80 s earlier than expected in observations from the TESS satellite. We present 22 new times of mid-transit that confirm the existence of transit timing variations, and are well fitted by a quadratic ephemeris with period decay dP/dt = −9.2 ± 1.1 ms yr−1. We rule out instrumental issues, stellar activity and the Applegate mechanism as possible causes. The light-time effect is also not favoured due to the non-detection of changes in the systemic velocity. Orbital decay and apsidal precession are plausible but unproven. WASP-4 b is only the third hot Jupiter known to show transit timing variations to high confidence. We discuss a variety of observations of this and other planetary systems that would be useful in improving our understanding of WASP-4 in particular and orbital decay in general.
Citation
Southworth , J , Dominik , M , Jorgensen , U G , Andersen , M I , Bozza , V , Burgdorf , M J , D'Ago , G , Dib , S , Figuera Jaimes , R , Fujii , Y I , Gill , S , Haikala , L K , Hinse , T C , Hundertmark , M , Khalouei , E , Korhonen , H , Longa-Peña , P , Mancini , L , Peixinho , N , Rabus , M , Rahvar , S , Sajadian , S , Skottfelt , J , Snodgrass , C , Spyratos , P , Tregloan-Reed , J , Unda-Sanzana , E & von Essen , C 2019 , ' Transit timing variations in the WASP-4 planetary system ' , Monthly Notices of the Royal Astronomical Society , vol. 490 , no. 3 , pp. 4230-4236 . https://doi.org/10.1093/mnras/stz2602
Publication
Monthly Notices of the Royal Astronomical Society
Status
Peer reviewed
ISSN
1365-2966Type
Journal article
Collections
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