Direct Imaging Discovery of Giant Exoplanet β Pictoris d: A Decade-long Game of Hide-and-seek
Year: 2026
Type: article
Abstract: We report the direct imaging discovery of a third exoplanet in the β Pictoris ( β Pic) system. We detect β Pictoris d ( β Pic d) in noncoronagraphic observations obtained with the Very Large Telescope (VLT) Enhanced Resolution Imager and Spectrograph (ERIS), as well as multi-epoch archival datasets from the JWST Near Infrared Camera (NIRCam) and VLT/SPHERE. Astrometric measurements over an 11 yr baseline demonstrate that it is consistent with a gravitationally bound source with orbital motion. Joint multi-planet orbit fits of all three planets in the system yield a semimajor axis of 26 . 0 − 6.1 + 2.2 au and inclination 89 . 0 − 0.6 + 0.7 deg for planet d. β Pic d has a larger orbital semimajor axis than the other known planets in the system, but is coplanar with the inner two planets, and its orbit is consistent with sculpting the inner edge of the debris disk. β Pic d has a contrast of Δ L ′ = 12.11 ± 0.15 mag, with colors and luminosity that closely match those of 51 Eri b, another exoplanet in the β Pic moving group. Its VLT/ERIS and JWST/NIRCam colors are distinct from those of free-floating planetary-mass objects of a similar age and temperature. Its red F410M − F444W color indicates strong CO 2 absorption in its atmosphere and suggests significant enhancement in metals compared to free-floating objects. From the ATMO hot-start evolutionary models, we estimate an effective temperature of 60 0 − 60 + 45 K and mass of 2.4 ± 0.6 M Jup , which also closely matches similar estimates for 51 Eri b. β Pic d is among the lowest-mass exoplanets imaged from the ground. This discovery highlights the deep sensitivity achievable with ground-based imaging in the mid-infrared and the discovery potential of future high-contrast observations with the Extremely Large Telescope.
Authors: Ben J. Sutlieff, Markus J. Bonse, Valentin Christiaens, Clémence Fontanive, Elisabeth C. Matthews, Luke T. Parker, Tim D. Pearce, Jayne L. Birkby, Beth A. Biller, Trent J. Dupuy, Emily O. Garvin, Leyla Iskandarli, Jens Kammerer, Yifan Zhou, Robert J. De Rosa, Aarynn L. Carter, Sasha Hinkley, Matthew A. Kenworthy, William O. Balmer, Iain Hammond, James Mang, Caroline V. Morley, Mark J. Neeser, Olivier Absil, Anthony Boccaletti, Mariangela Bonavita, Brendan P. Bowler, Xueqing Chen, Felix A. Dannert, Julien H. Girard, Markus Kasper, Anne-Marie Lagrange, Pengyu Liu, Gilles Orban de Xivry, Michael Poon, Sascha P. Quanz, Benoît Serra, Johanna M. Vos, Kevin Wagner, Jason Wang, Bernhard Schölkopf, Guido Agapito, Alex Agudo Berbel, Dániel Apai, Andrea Baruffolo, Martin Black, Marco Bonaglia, Runa Briguglio, Yixian Cao, Luca Carbonaro, Lee Chapman, Giovanni Cresci, Yigit Dallilar, Richard Davies, Matthias Deysenroth, Ivan Di Antonio, Amico Di Cianno, Gianluca Di Rico, David Doelman, Mauro Dolci, Frank Eisenhauer, Simone Esposito, Debora Ferruzzi, Helmut Feuchtgruber, Natascha Förster-Schreiber, Kyle Franson, Reinhard Genzel, Stefan Gillessen, Eileen C. Gonzales, Michael Hartl, Jean Hayoz, Heinrich Huber, Christoph Keller, Kateryna Kravchenko, Jarron Leisenring, John Lightfoot, David Lunney, Dieter Lutz, Mike Macintosh, Filippo Mannucci, Stanimir Metchev, Thomas Ott, David Pearson, Alfio Puglisi, Sebastian Rabien, Christian Rau, Armando Riccardi, Bernardo Salasnich, Taro Shimizu, Frans Snik, Eckhard Sturm, Genaro Suárez, Linda Tacconi, Xianyu Tan, William Taylor, Christopher Waring, Marco Xompero
Institutions: University of Edinburgh, European Southern Observatory, European Southern Observatory, Max Planck Institute for Intelligent Systems, University of Liège, Université Paris-Saclay, American Museum of Natural History, Max Planck Institute for Astronomy, University of Oxford, University of Warwick, Institute for Particle Physics and Astrophysics, University of Virginia, Space Telescope Science Institute, University of Exeter, Leiden University, Johns Hopkins University, The University of Texas at Austin, Université Paris Sciences et Lettres, University of California, Santa Barbara, Université Grenoble Alpes, University of Toronto, ETH Zurich, Trinity College Dublin, University of Arizona, Northwestern University, Arcetri Astrophysical Observatory, National Institute for Astrophysics, Max Planck Institute for Extraterrestrial Physics, Massachusetts Institute of Technology, Osservatorio Astronomico di Padova, UK Astronomy Technology Centre, University of Cologne, Collurania Teramo Observatory, University of California System, San Francisco State University, National Solar Observatory, Western University, Shanghai Jiao Tong University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,400
Funders: National Science Foundation, National Aeronautics and Space Administration, California Institute of Technology, Space Telescope Science Institute, UK Research and Innovation, NASA Exoplanet Science Institute, Breakthrough Prize Foundation, European Space Agency, Leverhulme Trust, University of Warwick, European Commission, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Fonds De La Recherche Scientifique - FNRS, Science and Technology Facilities Council, Agencia Estatal de Investigación, Research Ireland
Awards: G103270039, G1338664626, G2191281307, G2452073530, G256731684, OrChemSTAR – Organic Chemistry Science Teaching and Learning with Augmented Reality, TCF4 transcriptional program in crypt stem cells and resulting differentiated cells, G3452655474, Astronomy and Astrophysics at Edinburgh, Direct Imaging Characterisation of Exoplanets: Studying Storms and Searching for Saturns, G4276578120, G5180915604, G5195188938, G5197612414, G5458454780, G5492458037, G5568641063, G5929972803, Governing the young poor in Switzerland: How the moral foundations of work ethics guide social assistance discourse, G6111749634, G6115201310, G6686480456, NCCR PlanetS: Origin, evolution and characterisation of planets, G6895475279, Constraining gas giant planet formation via high-contrast exoplanet imaging, G7312380752, G7650087473, G8059689707, G8127641968, G8318038168, G8428221222, G8505061131, G8827130585, The Power of Dynamical Masses: a JWST and VLTI/GRAVITY Direct Imaging Survey for Exoplanets, G8867727975, G9000386741
OpenAlex ID: W7168366530