CO, H₂O, and CH₄in the dusty atmosphere of a ≲ 5 Myr-old exoplanet

Author(s)

Eric Gaidos, Teruyuki Hirano

Abstract

Very young massive planets are sufficiently luminous by their internal heat of formation to permit detailed studies, including spectroscopy of their atmospheres with large telescopes at sufficient resolution (λ/Δλ 1000) to identify major constituents to inform models of planet formation and early evolution. We obtained 1-2.4 μm (YJHK) spectra of the planetary-mass 'b' companion of 2MASS J04372171+2651014, a 1-3 Myr-old M dwarf member of the Taurus star-forming region, and one of the youngest such objects discovered to date. These indicate the presence of CO and possibly H2O and CH4 in the atmosphere, all suggesting a Teff of around 1200 K, characteristic of a L-T transition spectral type and consistent with previous estimates based on its luminosity and age. The absence or attenuation of spectral features at shorter wavelengths suggests the presence of micron-size dust, consistent with the object's red colour. The spectrum of 2M0437b resembles those of the HR 8799 planets, especially the innermost 'b' planet, with the exception of a pronounced flux deficit in the H-band of uncertain origin.

Organisation(s)

Department of Astrophysics

External organisation(s)

University of Hawaii at Manoa, National Institutes of Natural Sciences (NINS), National Astronomical Observatory of Japan

Journal

Monthly Notices of the Royal Astronomical Society

Volume

525

Pages

6303-6311

No. of pages

9

ISSN

0035-8711

DOI

https://doi.org/10.1093/mnras/stad2664

Publication date

11-2023

Peer reviewed

Yes

Austrian Fields of Science 2012

103003 Astronomy, 103004 Astrophysics

Keywords

ASJC Scopus subject areas

Astronomy and Astrophysics, Space and Planetary Science

Portal url

https://ucrisportal.univie.ac.at/en/publications/db77c955-ac0c-4be6-b2c7-062fe4fbc8a0