A closer look at LTT 9779b: The ESPRESSO endeavour to pierce the atmospheric veil

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Reyes, R. Ramírez, Jenkins, James S., Sedaghati, Elyar, Seidel, J. V., Pavlenko, Yakiv, Palle, E., López-Morales, Mercedes, Alves, Douglas, Vines, José, R, Pablo A. Peña, Díaz, Matías R., Rojo, Patricio
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917906514706432
author Reyes, R. Ramírez
Jenkins, James S.
Sedaghati, Elyar
Seidel, J. V.
Pavlenko, Yakiv
Palle, E.
López-Morales, Mercedes
Alves, Douglas
Vines, José
R, Pablo A. Peña
Díaz, Matías R.
Rojo, Patricio
author_facet Reyes, R. Ramírez
Jenkins, James S.
Sedaghati, Elyar
Seidel, J. V.
Pavlenko, Yakiv
Palle, E.
López-Morales, Mercedes
Alves, Douglas
Vines, José
R, Pablo A. Peña
Díaz, Matías R.
Rojo, Patricio
contents The proliferation of exoplanet discoveries in exotic environments like the Neptune desert challenges our understanding of planetary atmospheres under intense irradiation. The unexpected discovery of LTT9779 b, an ultra-hot Neptune within this desert, offers a prime opportunity for atmospheric studies. We build on prior observations of LTT9779 b from TESS, Spitzer, and CHEOPS, incorporating new VLT/ESPRESSO data to probe its atmospheric dynamics. Preliminary analyses suggest a metal-rich atmosphere and a high day-side geometric albedo, possibly indicating silicate clouds. Minimal atmospheric escape is observed, contrasting existing models of planetary evolution under extreme irradiation. We obtained the transmission spectrum of LTT9779 b between 0.4 and 0.78 microns with ESPRESSO, addressing systematics across three transits. Our analysis focused on the sodium doublet and H-alpha, using cross-correlation with models containing Na, K, FeH, TiO, and VO. No significant atmospheric signal was detected, with metallicity limits set at [Fe/H] $\geq$ 2.25 ($\geq$ 180 times solar). The non-detection aligns with a high-metallicity, cloud-free model, implying a high mean molecular weight and reduced atmospheric scale height. We interpret this as evidence for a metal-rich atmosphere with suppressed spectral features, possibly due to high-altitude clouds or hazes. These findings are consistent with JWST observations, supporting the hypothesis of metal-rich atmospheres obscured by aerosols in extreme environments.
format Preprint
id arxiv_https___arxiv_org_abs_2501_17272
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A closer look at LTT 9779b: The ESPRESSO endeavour to pierce the atmospheric veil
Reyes, R. Ramírez
Jenkins, James S.
Sedaghati, Elyar
Seidel, J. V.
Pavlenko, Yakiv
Palle, E.
López-Morales, Mercedes
Alves, Douglas
Vines, José
R, Pablo A. Peña
Díaz, Matías R.
Rojo, Patricio
Earth and Planetary Astrophysics
The proliferation of exoplanet discoveries in exotic environments like the Neptune desert challenges our understanding of planetary atmospheres under intense irradiation. The unexpected discovery of LTT9779 b, an ultra-hot Neptune within this desert, offers a prime opportunity for atmospheric studies. We build on prior observations of LTT9779 b from TESS, Spitzer, and CHEOPS, incorporating new VLT/ESPRESSO data to probe its atmospheric dynamics. Preliminary analyses suggest a metal-rich atmosphere and a high day-side geometric albedo, possibly indicating silicate clouds. Minimal atmospheric escape is observed, contrasting existing models of planetary evolution under extreme irradiation. We obtained the transmission spectrum of LTT9779 b between 0.4 and 0.78 microns with ESPRESSO, addressing systematics across three transits. Our analysis focused on the sodium doublet and H-alpha, using cross-correlation with models containing Na, K, FeH, TiO, and VO. No significant atmospheric signal was detected, with metallicity limits set at [Fe/H] $\geq$ 2.25 ($\geq$ 180 times solar). The non-detection aligns with a high-metallicity, cloud-free model, implying a high mean molecular weight and reduced atmospheric scale height. We interpret this as evidence for a metal-rich atmosphere with suppressed spectral features, possibly due to high-altitude clouds or hazes. These findings are consistent with JWST observations, supporting the hypothesis of metal-rich atmospheres obscured by aerosols in extreme environments.
title A closer look at LTT 9779b: The ESPRESSO endeavour to pierce the atmospheric veil
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2501.17272