skip to main content

Title: DIRECT IMAGING OF A COLD JOVIAN EXOPLANET IN ORBIT AROUND THE SUN-LIKE STAR GJ 504

Several exoplanets have recently been imaged at wide separations of >10 AU from their parent stars. These span a limited range of ages (<50 Myr) and atmospheric properties, with temperatures of 800-1800 K and very red colors (J - H > 0.5 mag), implying thick cloud covers. Furthermore, substantial model uncertainties exist at these young ages due to the unknown initial conditions at formation, which can lead to an order of magnitude of uncertainty in the modeled planet mass. Here, we report the direct-imaging discovery of a Jovian exoplanet around the Sun-like star GJ 504, detected as part of the SEEDS survey. The system is older than all other known directly imaged planets; as a result, its estimated mass remains in the planetary regime independent of uncertainties related to choices of initial conditions in the exoplanet modeling. Using the most common exoplanet cooling model, and given the system age of 160{sup +350}{sub -60} Myr, GJ 504b has an estimated mass of 4{sup +4.5}{sub -1.0} Jupiter masses, among the lowest of directly imaged planets. Its projected separation of 43.5 AU exceeds the typical outer boundary of {approx}30 AU predicted for the core accretion mechanism. GJ 504b is also significantly cooler (510{supmore » +30}{sub -20} K) and has a bluer color (J - H = -0.23 mag) than previously imaged exoplanets, suggesting a largely cloud-free atmosphere accessible to spectroscopic characterization. Thus, it has the potential of providing novel insights into the origins of giant planets as well as their atmospheric properties.« less
Authors:
 [1] ; ; ; ; ; ; ;  [2] ;  [3] ; ; ; ; ; ;  [4] ;  [5] ; ;  [6] ;  [7] ;  [8] more »; « less
  1. Department of Earth and Planetary Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)
  2. National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
  3. Subaru Telescope, National Astronomical Observatory of Japan, 650 North A'ohoku Place, Hilo, HI 96720 (United States)
  4. Department of Astrophysical Sciences, Princeton University, Peyton Hall, Ivy Lane, Princeton, NJ 08544 (United States)
  5. Astronomical Institute ''Anton Pannekoek'', University of Amsterdam, Postbus 94249, 1090 GE, Amsterdam (Netherlands)
  6. Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany)
  7. Department of Physics and Astronomy, College of Charleston, 58 Coming Street, Charleston, SC 29424 (United States)
  8. Exoplanets and Stellar Astrophysics Laboratory, Code 667, Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
Publication Date:
OSTI Identifier:
22133993
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 774; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CLOUD COVER; COLOR; COOLING; MASS; ORBITS; PLANETARY ATMOSPHERES; PLANETS; SIMULATION; STARS