Home News About Us Contact Contributors Disclaimer Privacy Policy Help FAQ

Home
Search
Quick Search
Advanced
Fulltext
Browse
Collections
Persons
My eDoc
Session History
Login
Name:
Password:
Documentation
Help
Support Wiki
Direct access to
document ID:


          Institute: MPI für Astronomie     Collection: Publikationen_mpia     Display Documents



ID: 731783.0, MPI für Astronomie / Publikationen_mpia
The LEECH Exoplanet Imaging Survey: Characterization of the Coldest Directly Imaged Exoplanet, GJ 504 b, and Evidence for Superstellar Metallicity
Authors:Skemer, A. J.; Morley, C. V.; Zimmerman, N. T.; Skrutskie, M. F.; Leisenring, J.; Buenzli, E.; Bonnefoy, M.; Bailey, V.; Hinz, P.; Defrére, D.; Esposito, S.; Apai, D.; Biller, B.; Brandner, W.; Close, L.; Crepp, J. R.; De Rosa, R. J.; Desidera, S.; Eisner, J.; Fortney, J.; Freedman, R.; Henning, T.; Hofmann, K.-H.; Kopytova, T.; Lupu, R.; Maire, A.-L.; Males, J. R.; Marley, M.; Morzinski, K.; Oza, A.; Patience, J.; Rajan, A.; Rieke, G.; Schertl, D.; Schlieder, J.; Stone, J.; Su, K.; Vaz, A.; Visscher, C.; Ward-Duong, K.; Weigelt, G.; Woodward, C. E.
Date of Publication (YYYY-MM-DD):2016
Title of Journal:The Astrophysical Journal
Volume:817
Issue / Number:2
Start Page:id. 166 (10 pp)
Audience:Not Specified
Abstract / Description:As gas giant planets and brown dwarfs radiate away the residual heat from their formation, they cool through a spectral type transition from L to T, which encompasses the dissipation of cloud opacity and the appearance of strong methane absorption. While there are hundreds of known T-type brown dwarfs, the first generation of directly imaged exoplanets were all L type. Recently, Kuzuhara et al. announced the discovery of GJ 504 b, the first T dwarf exoplanet. GJ 504 b provides a unique opportunity to study the atmosphere of a new type of exoplanet with a ∼500 K temperature that bridges the gap between the first directly imaged planets (∼1000 K) and our own solar system's Jupiter (∼130 K). We observed GJ 504 b in three narrow L-band filters (3.71, 3.88, and 4.00 μm), spanning the red end of the broad methane fundamental absorption feature (3.3 μm) as part of the LBTI Exozodi Exoplanet Common Hunt (LEECH) exoplanet imaging survey. By comparing our new photometry and literature photometry with a grid of custom model atmospheres, we were able to fit GJ 504 b's unusual spectral energy distribution for the first time. We find that GJ 504 b is well fit by models with the following parameters: Teff = 544 ± 10 K, g < 600 m s‑2, [M/H] = 0.60 ± 0.12, cloud opacity parameter of fsed = 2–5, R = 0.96 ± 0.07 RJup, and log(L) = ‑6.13 ± 0.03 L, implying a hot start mass of 3–30 Mjup for a conservative age range of 0.1–6.5 Gyr. Of particular interest, our model fits suggest that GJ 504 b has a superstellar metallicity. Since planet formation can create objects with nonstellar metallicities, while binary star formation cannot, this result suggests that GJ 504 b formed like a planet, not like a binary companion. The LBT is an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are the University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrophisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The Ohio State University, and the Research Corporation, on behalf of the University of Notre Dame, University of Minnesota, and University of Virginia.
Free Keywords:planets and satellites: atmospheres; planets and satellites: composition; planets and satellites: gaseous planets; stars: individual: GJ 504
External Publication Status:published
Document Type:Article
Communicated by:N. N.
Affiliations:MPI für Astronomie
Identifiers:ISSN:0004-637X
URL:http://cdsads.u-strasbg.fr/abs/2016ApJ...817..166S
The scope and number of records on eDoc is subject to the collection policies defined by each institute - see "info" button in the collection browse view.