Transmission spectroscopy of WASP-52 b with JWST NIRISS: Water and helium atmospheric absorption, alongside prominent star-spot crossings
Fuente:
arXiv
Guardado en:
| Autores principales: | , , , , , , , , , , , , , , , , , , , , , , |
|---|---|
| Formato: | Preprint |
| Publicado: |
2024
|
| Materias: | |
| Acceso en línea: | |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| _version_ | 1866914461924720640 |
|---|---|
| author | Fournier-Tondreau, Marylou Pan, Yanbo Morel, Kim Lafrenière, David MacDonald, Ryan J. Coulombe, Louis-Philippe Allart, Romain Albert, Loïc Radica, Michael Piaulet-Ghorayeb, Caroline Roy, Pierre-Alexis Pelletier, Stefan Dang, Lisa Doyon, René Benneke, Björn Cowan, Nicolas B. Darveau-Bernier, Antoine Lim, Olivia Artigau, Étienne Johnstone, Doug Kaltenegger, Lisa Taylor, Jake Flagg, Laura |
| author_facet | Fournier-Tondreau, Marylou Pan, Yanbo Morel, Kim Lafrenière, David MacDonald, Ryan J. Coulombe, Louis-Philippe Allart, Romain Albert, Loïc Radica, Michael Piaulet-Ghorayeb, Caroline Roy, Pierre-Alexis Pelletier, Stefan Dang, Lisa Doyon, René Benneke, Björn Cowan, Nicolas B. Darveau-Bernier, Antoine Lim, Olivia Artigau, Étienne Johnstone, Doug Kaltenegger, Lisa Taylor, Jake Flagg, Laura |
| contents | In the era of exoplanet studies with JWST, the transiting, hot gas giant WASP-52 b provides an excellent target for atmospheric characterization through transit spectroscopy. WASP-52 b orbits an active K-type dwarf recognized for its surface heterogeneities, such as star-spots and faculae, which offers challenges to atmospheric characterization via transmission spectroscopy. Previous transit observations have detected active regions on WASP-52 through crossing events in transit light-curves and via the spectral imprint of unocculted magnetic regions on transmission spectra. Here, we present the first JWST observations of WASP-52 b. Our JWST NIRISS/SOSS transit observation, obtained through the GTO 1201 Program, detects two clear spot-crossing events that deform the 0.6-2.8 $μ$m transit light-curves of WASP-52 b. We find that these two occulted spots combined cover about 2.4 % of the stellar surface and have temperatures about 400-500 K colder than the stellar photosphere. Our NIRISS/SOSS transmission spectrum is best-fit by an atmosphere with H$_2$O (10.8 $σ$), He (7.3 $σ$, with evidence of an escaping tail at $\sim$ 2.9 $σ$), hints of K (2.5 $σ$), and unocculted star-spots and faculae (3.6 $σ$). The retrieved H$_2$O abundance ($\log$ H$_2$O $\approx -4 \pm 1$) is consistent with a subsolar or solar atmospheric metallicity for two independent data reductions. Our results underscore the importance of simultaneously modelling planetary atmospheres and unocculted stellar heterogeneities when interpreting transmission spectra of planets orbiting active stars and demonstrate the necessity of considering different stellar contamination models that account for both cold and hot active regions. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2412_17072 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Transmission spectroscopy of WASP-52 b with JWST NIRISS: Water and helium atmospheric absorption, alongside prominent star-spot crossings Fournier-Tondreau, Marylou Pan, Yanbo Morel, Kim Lafrenière, David MacDonald, Ryan J. Coulombe, Louis-Philippe Allart, Romain Albert, Loïc Radica, Michael Piaulet-Ghorayeb, Caroline Roy, Pierre-Alexis Pelletier, Stefan Dang, Lisa Doyon, René Benneke, Björn Cowan, Nicolas B. Darveau-Bernier, Antoine Lim, Olivia Artigau, Étienne Johnstone, Doug Kaltenegger, Lisa Taylor, Jake Flagg, Laura Earth and Planetary Astrophysics In the era of exoplanet studies with JWST, the transiting, hot gas giant WASP-52 b provides an excellent target for atmospheric characterization through transit spectroscopy. WASP-52 b orbits an active K-type dwarf recognized for its surface heterogeneities, such as star-spots and faculae, which offers challenges to atmospheric characterization via transmission spectroscopy. Previous transit observations have detected active regions on WASP-52 through crossing events in transit light-curves and via the spectral imprint of unocculted magnetic regions on transmission spectra. Here, we present the first JWST observations of WASP-52 b. Our JWST NIRISS/SOSS transit observation, obtained through the GTO 1201 Program, detects two clear spot-crossing events that deform the 0.6-2.8 $μ$m transit light-curves of WASP-52 b. We find that these two occulted spots combined cover about 2.4 % of the stellar surface and have temperatures about 400-500 K colder than the stellar photosphere. Our NIRISS/SOSS transmission spectrum is best-fit by an atmosphere with H$_2$O (10.8 $σ$), He (7.3 $σ$, with evidence of an escaping tail at $\sim$ 2.9 $σ$), hints of K (2.5 $σ$), and unocculted star-spots and faculae (3.6 $σ$). The retrieved H$_2$O abundance ($\log$ H$_2$O $\approx -4 \pm 1$) is consistent with a subsolar or solar atmospheric metallicity for two independent data reductions. Our results underscore the importance of simultaneously modelling planetary atmospheres and unocculted stellar heterogeneities when interpreting transmission spectra of planets orbiting active stars and demonstrate the necessity of considering different stellar contamination models that account for both cold and hot active regions. |
| title | Transmission spectroscopy of WASP-52 b with JWST NIRISS: Water and helium atmospheric absorption, alongside prominent star-spot crossings |
| topic | Earth and Planetary Astrophysics |
| url | https://arxiv.org/abs/2412.17072 |