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 1-2.4μm (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 1200K, 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 color. 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.
Eric Gaidos, Teruyuki Hirano
Comments: accepted to MNRAS
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2308.13745 [astro-ph.EP] (or arXiv:2308.13745v1 [astro-ph.EP] for this version)
Submission history
From: Eric Gaidos
[v1] Sat, 26 Aug 2023 03:11:22 UTC (1,615 KB)
https://arxiv.org/abs/2308.13745
Astrobiology, Astrochemistry,
