Hot Jupiters are giant Jupiter-like exoplanets that orbit their host stars 100 times more closely than Jupiter orbits the Sun. These planets presumably form in the outer part of the primordial disk from which both the central star and surrounding planets are born, then migrate inwards and yet avoid falling into their host star1. It is, however, unclear whether this occurs early in the lives of hot Jupiters, when they are still embedded within protoplanetary disks2, or later, once multiple planets are formed and interact3. Although numerous hot Jupiters have been detected around mature Sun-like stars, their existence has not yet been firmly demonstrated for young stars4,5,6, whose magnetic activity is so intense that it overshadows the radial velocity signal that close-in giant planets can induce. Here we report that the radial velocities of the young star V830 Tau exhibit a sine wave of period 4.93 days and semi-amplitude 75 metres per second, detected with a false-alarm probability of less than 0.03 per cent, after filtering out the magnetic activity plaguing the spectra. We find that this signal is unrelated to the 2.741-day rotation period of V830 Tau and we attribute it to the presence of a planet of mass 0.77 times that of Jupiter, orbiting at a distance of 0.057 astronomical units from the host star. Our result demonstrates that hot Jupiters can migrate inwards in less than two million years, probably as a result of planet–disk interactions2.
Access optionsAccess options
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
This paper is based on observations obtained at the CFHT Corporation (operated by the National Research Council of Canada, the Institut National des Sciences de l’Univers of the Centre National de la Recherche Scientifique (INSU/CNRS) of France and the University of Hawaii), at the Télescope Bernard Lyot (TBL) (operated by the Observatoire Midi-Pyrénées and by INSU/CNRS), and at the Gemini Observatory (operated by the Association of Universities for Research in Astronomy under a cooperative agreement with the National Science Foundation (NSF) on behalf of the Gemini partnership: the NSF of the United States, the National Research Council of Canada, CONICyT of Chile, the Ministerio de Ciencia, Tecnología e Innovación Productiva of Argentina, and the Ministério da Ciência, Tecnologia e Inovação of Brazil). We thank the Queue Service Observing teams of CFHT, TBL and the Gemini Observatory, without whom this study would not have been possible. We also thank the IDEX initiative of Université Fédérale Toulouse Midi-Pyrénées for awarding a ‘Chaire d’Attractivité’ to G.H., in the framework of which this work was done. S.A. acknowledges financial support from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and Fundação de Amparo a Pesquisa do Estado de Minas Gerais (Fapemig).