The JWST Early-Release Science Program for Direct Observations of Exoplanetary Systems Ii: A 1 To 20 Μm Spectrum of the Planetary-Mass Companion Vhs 1256-1257 B

Authors

• Brittany E. Miles, University of California, Santa Cruz
• Beth A. Biller, University of Edinburgh, Institute for Astronomy
• Polychronis Patapis, ETH Zürich
• Kadin Worthen, Johns Hopkins University
• Emily Rickman, European Space Agency - ESA
• Kielan K.W. Hoch, Center for Astrophysics & Space Sciences
• Andrew Skemer, University of California, Santa Cruz
• Marshall D. Perrin, Space Telescope Science Institute
• Niall Whiteford, American Museum of Natural History
• Christine H. Chen, Johns Hopkins University
• B. Sargent, Center for Astrophysics & Space Sciences
• Sagnick Mukherjee, University of California, Santa Cruz
• Caroline V. Morley, The University of Texas at Austin
• Sarah E. Moran, The University of Arizona
• Mickael Bonnefoy, Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
• Simon Petrus, Universidad de Valparaiso
• Aarynn L. Carter, University of California, Santa Cruz
• Elodie Choquet, Laboratoire d'Astrophysique de Marseille
• Sasha Hinkley, University of Exeter
• Kimberly Ward-Duong, Smith CollegeFollow
• Jarron M. Leisenring, The University of Arizona
• Maxwell A. Millar-Blanchaer, University of California, Santa Barbara
• Laurent Pueyo, Space Telescope Science Institute
• Shrishmoy Ray, University of Exeter
• Steph Sallum, University of California, Irvine
• Karl R. Stapelfeldt, California Institute of Technology
• Jordan M. Stone, Naval Research Laboratory
• Jason J. Wang, Northwestern University
• Olivier Absil, Université de Liège
• William O. Balmer, Johns Hopkins University
• Anthony Boccaletti, L'Observatoire de Paris
• Mariangela Bonavita, The Open University

Document Type

Article

Publication Date

3-1-2023

Publication Title

Astrophysical Journal Letters

Abstract

We present the highest fidelity spectrum to date of a planetary-mass object. VHS 1256 b is a (∼8″, a = 150 au), young, planetary-mass companion that shares photometric colors and spectroscopic features with the directly imaged exoplanets HR 8799c, d, and e. As an L-to-T transition object, VHS 1256 b exists along the region of the color-magnitude diagram where substellar atmospheres transition from cloudy to clear. We observed VHS 1256 b with JWST's NIRSpec IFU and MIRI MRS modes for coverage from 1 to 20 μm at resolutions of ∼1000-3700. Water, methane, carbon monoxide, carbon dioxide, sodium, and potassium are observed in several portions of the JWST spectrum based on comparisons from template brown dwarf spectra, molecular opacities, and atmospheric models. The spectral shape of VHS 1256 b is influenced by disequilibrium chemistry and clouds. We directly detect silicate clouds, the first such detection reported for a planetary-mass companion.

Volume

946

Issue

1

DOI

https://doi.org/10.3847/2041-8213/acb04a

ISSN

20418205

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Rights

© 2023. The Author(s).

Version

Version of Record

Recommended Citation

Miles, Brittany E.; Biller, Beth A.; Patapis, Polychronis; Worthen, Kadin; Rickman, Emily; Hoch, Kielan K.W.; Skemer, Andrew; Perrin, Marshall D.; Whiteford, Niall; Chen, Christine H.; Sargent, B.; Mukherjee, Sagnick; Morley, Caroline V.; Moran, Sarah E.; Bonnefoy, Mickael; Petrus, Simon; Carter, Aarynn L.; Choquet, Elodie; Hinkley, Sasha; Ward-Duong, Kimberly; Leisenring, Jarron M.; Millar-Blanchaer, Maxwell A.; Pueyo, Laurent; Ray, Shrishmoy; Sallum, Steph; Stapelfeldt, Karl R.; Stone, Jordan M.; Wang, Jason J.; Absil, Olivier; Balmer, William O.; Boccaletti, Anthony; and Bonavita, Mariangela, "The JWST Early-Release Science Program for Direct Observations of Exoplanetary Systems Ii: A 1 To 20 Μm Spectrum of the Planetary-Mass Companion Vhs 1256-1257 B" (2023). Astronomy: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/ast_facpubs/88