title: RETRACTED: Direct imaging discovery of a Jovian exoplanet within a triple-star system.
abstract: Direct imaging allows for the detection and characterization of exoplanets via their thermal emission. We report the discovery via imaging of a young Jovian planet in a triple-star system and characterize its atmospheric properties through near-infrared spectroscopy. The semimajor axis of the planet is closer relative to that of its hierarchical triple-star system than for any known exoplanet within a stellar binary or triple, making HD 131399 dynamically unlike any other known system. The location of HD 131399Ab on a wide orbit in a triple system demonstrates that massive planets may be found on long and possibly unstable orbits in multistar systems. HD 131399Ab is one of the lowest mass (4 ± 1 Jupiter masses) and coldest (850 ± 50 kelvin) exoplanets to have been directly imaged.
authors.affiliation: Department of Astronomy and Steward Observatory, The University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA. kwagner@as.arizona.edu.
authors.forename: Kevin
authors.initials: K
authors.lastname: Wagner
authors.affiliation: Department of Astronomy and Steward Observatory, The University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA. Lunar and Planetary Laboratory, The University of Arizona, 1640 East University Boulevard, Tucson, AZ 85718, USA.
authors.forename: Dániel
authors.initials: D
authors.lastname: Apai
authors.affiliation: European Southern Observatory (ESO), Karl-Schwarzschild-Strasse 2, D-85748 Garching, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Kasper
authors.affiliation: Department of Astronomy and Steward Observatory, The University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA.
authors.forename: Kaitlin
authors.initials: K
authors.lastname: Kratter
authors.affiliation: European Southern Observatory (ESO), Karl-Schwarzschild-Strasse 2, D-85748 Garching, Germany.
authors.forename: Melissa
authors.initials: M
authors.lastname: McClure
authors.affiliation: Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA. Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218, USA.
authors.forename: Massimo
authors.initials: M
authors.lastname: Robberto
authors.affiliation: Université Grenoble Alpes, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), F-38000 Grenoble, France. CNRS, IPAG, F-38000 Grenoble, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Beuzit