HAT-P-32 b: what can be deduced from transit observations in Hα and He I lines?

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: F., Shaikhislamov I., S, Sharipov S., L., Khodachenko M., B., Miroshnichenko I., S., Rumenskikh M., P., Golubovsky M., G, Berezutsky A.
Formato: Preprint
Publicado: 2026
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866917342140694528
author F., Shaikhislamov I.
S, Sharipov S.
L., Khodachenko M.
B., Miroshnichenko I.
S., Rumenskikh M.
P., Golubovsky M.
G, Berezutsky A.
author_facet F., Shaikhislamov I.
S, Sharipov S.
L., Khodachenko M.
B., Miroshnichenko I.
S., Rumenskikh M.
P., Golubovsky M.
G, Berezutsky A.
contents HAT-P-32 b is the first exoplanet for which absorption in hydrogen and helium lines has been measured simultaneously. In addition to the relatively large maximum depth of ~5% in both lines, observations have revealed very long pre-transit signatures. In this paper, we apply a 3D aeronomy model to simulate the detailed spectrally resolved absorption profiles at mid-transit, formed in the upper atmosphere, as well as the integral transit curves formed by atmospheric material accumulating around the star. By fitting the observations, we derive key atmospheric characteristics, including the atmospheric composition and metallicity, and constrain the stellar XUV, hard X-ray, and Lyα fluxes, as well as the intensity of the stellar plasma wind. We show that the presence of metals crucially affects the absorption in hydrogen and helium lines by accelerating the dissociation of H2. We also demonstrate that several processes not previously included in the modeling of HAT-P-32 b are important for the interpretation of the observations, such as the 3D asymmetric structure of the atmosphere, heating and cooling by excited states of hydrogen and metals, and the stellar VUV flux.
format Preprint
id arxiv_https___arxiv_org_abs_2603_14059
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle HAT-P-32 b: what can be deduced from transit observations in Hα and He I lines?
F., Shaikhislamov I.
S, Sharipov S.
L., Khodachenko M.
B., Miroshnichenko I.
S., Rumenskikh M.
P., Golubovsky M.
G, Berezutsky A.
Earth and Planetary Astrophysics
HAT-P-32 b is the first exoplanet for which absorption in hydrogen and helium lines has been measured simultaneously. In addition to the relatively large maximum depth of ~5% in both lines, observations have revealed very long pre-transit signatures. In this paper, we apply a 3D aeronomy model to simulate the detailed spectrally resolved absorption profiles at mid-transit, formed in the upper atmosphere, as well as the integral transit curves formed by atmospheric material accumulating around the star. By fitting the observations, we derive key atmospheric characteristics, including the atmospheric composition and metallicity, and constrain the stellar XUV, hard X-ray, and Lyα fluxes, as well as the intensity of the stellar plasma wind. We show that the presence of metals crucially affects the absorption in hydrogen and helium lines by accelerating the dissociation of H2. We also demonstrate that several processes not previously included in the modeling of HAT-P-32 b are important for the interpretation of the observations, such as the 3D asymmetric structure of the atmosphere, heating and cooling by excited states of hydrogen and metals, and the stellar VUV flux.
title HAT-P-32 b: what can be deduced from transit observations in Hα and He I lines?
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2603.14059